drilling directive for grade one geothermal resource
TRANSCRIPT
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WHEREAS, it is necessary to ensure the exploration and development of geothermal
resource are utilized for the most economic benefits of the Country by complying with the
applicable laws pertaining to the environment and the health and safety of the employees and the
surrounding community;
WHEREAS, carry out geothermal drilling operations in accordance with the appropriate
drilling technology consistent with international best practices generally accepted in the
geothermal industry;
WHEREAS, it is essential to introduce a general standard applicable to drilling
operations including drilling plan, drilling program, and well design plan, conducting drilling
operation and well abandonment for geothermal resource development.
This directive is issued by Ethiopian Energy Authority pursuant to the power vested in it by
Article 47(2) of Geothermal Resource Development Proclamation No. 981/2016.
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PART ONE
GENERAL
1. Issuing Authority
This Directive is issued by Ethiopian Energy Authority pursuant to the power vested in it
by Articles 47(2) of the Geothermal Resource Development Proclamation No. 981/2016.
2. Short title
This directive may be cited as the “Geothermal Resource Development Grade I Drilling
Directive No.______/2020”.
3. Definitions
In this Directive, unless the context requires otherwise,
1/ All the words defined in the Geothermal Resource Development Proclamation No
981/2016 and the Geothermal Resource Development of Council of Ministers
Regulations No. 453/2019 is applicable to this Directive.
2/ “Anchor Casing” means the cemented casing on which the permanent wellhead is
mounted and placed before production casing.
3/ “Conductor Pipe” means a short string of large-diameter pipe that is set into the well
first to provide the initial stable structural foundation for a borehole and to prevent the
sides of the hole and near the surface ground water from caving into the wellbore.
4/ “Direct Use” means utilization of geothermal resources for commercial, residential,
agricultural, public facilities, or other energy needs other than the commercial production
or generation of electricity. Direct use may occur under either a Grade I geothermal
license or a Grade II license.
5/ “Exploration Operations” mean any activity relating to the search for evidence of
geothermal resources, where you are physically present on the land and your activities
may cause damage to those lands. Exploration operations include, but not limited to,
geological, geophysical & geochemical operations, drilling temperature gradient wells,
drilling holes used for explosive charges for seismic exploration, core drilling or any
other drilling method, provided the well is not used for geothermal resource production.
It also includes related construction of roads and trails, and cross-country transit by
vehicles over public land. Exploration operations do not include the production or
utilization of geothermal resources.
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6/ “Licensee” means a natural or juridical person holding certain rights and responsibilities
granted under a geothermal license issued by Licensing Authority.
7/ “Operator means any person who has taken responsibility in writing for the operations
conducted on licensed lands.
8/ “Perforated/slotted Liner” means a wellbore tubular in which holes or slots have been
made before the string is assembled and run into the wellbore. Perforated/slotted liners
typically are used in open-hole sections within the reservoir where there is no need for
the liner to be cemented in place, as is required for zonal isolation.
9/ “Production Casing” means a casing string that is set above the reservoir interval and
within which the primary completion components are installed. Production casing serves
to isolate the reservoir from undesired fluids in the producing formation and from other
zones penetrated by the wellbore.
10/ “Subsequent Well Operations” are those operations done to a well after it has been
drilled. Examples of subsequent well operations include: cleaning the well out, surveying
it, performing well tests, chemical stimulation, running a liner or another casing string,
repairing existing casing, or converting the well from a production well to an injection
well or vice versa.
11/ “Surface Casing” is the first casing installed in the well that supports a drilling
wellhead. It is a pipe with a large diameter which is cemented to act as a protective shield
to preserve the water aquifers of the region.
12/ Any expression in the masculine gender includes the feminine.
4. Purpose
The purpose of this Directive is to set general standards applicable to geothermal drilling
operations including drilling plan, drilling program, and well design plan and well
abandonment for geothermal resource development.
5. Scope of Application
This directive shall apply throughout the Federal Democratic Republic of Ethiopia, with the
following exceptions:
1/ Pre-existing Wells Exemption
The Licensing Authority, after inspecting a pre-existing geothermal well and finding
it to be in good working condition, may “grandfather”, i.e. exempt, that well from the
provisions of this directive if there is no change on status of the well.
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2/ Small Non-commercial Self Use Exemption
The Licensing Authority may exempt any shallow (less than 200 meters total depth)
geothermal well from this directive if the resource is used in a residential or in a non-
commercial manner.
PART TWO
ACTIONS THAT NEED LICENSING AUTHORITY NOTICE AND GET PERMIT
6. Intension to Drill
Before a Licensee or Operator can commence drilling a well, an application must be filed
on a prescribed form attached in Appendix-D and submitted to the Licensing Authority,
accompanied by the prescribed fee and environmental fund as stated in the regulation. The
Operator shall not commence drilling until the Licensing Authority approves and give
drilling permit to the application. The application shall include drilling plan, drilling
program, well design plan and, any information as reasonably required. After receiving the
application, the Licensing Authority will respond in a specified time in accordance with the
regulation.
7. Requirements of Drilling Plan
A drilling plan describes the overall program of the project which includes the complete
plan of the development of the drilling project and environment, health and safety plan.
The drilling plan includes but not limited to:
1/ The project site location map which includes drilling site locations, water well
locations, camp site, drilling mud storage (drilling sump);
2/ The overall planned/anticipated infrastructure and civil work facilities required for
the project incorporating planned roads, pipelines, wells, sumps, water source
development, water storage facilities, and generation plant;
3/ The overall health and safety plan of the project and implementation plan;
4/ Environment and community Implementation plan;
5/ Any other reasonable information the Licensing Authority may require.
8. Requirements of Drilling Program
A drilling program describes all the operational aspects of the well drilling proposal, well
completion and well logging and testing. In addition to requirements listed in Article 41(3)
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of the Regulation, the drilling program includes:-
1/ General scope of work including description of the equipment, materials, and
procedures to be used;
2/ Type of drilling rig and drilling materials like drilling fluids, a drilling string
assembly, cementing materials and other necessary drilling tools and equipments;
3/ The anticipated depth of the well(s) and trajectory of the well;
4/ The proposed bottom hole location and distances from the nearest license boundary;
5/ For deviated wells, provide the kick-off point; the direction of deviation, the angle of
build-up and maximum angle and plan and cross section maps indicating the surface
and bottom hole locations.
6/ Site preparation and civil works section describing, site leveling, sump and the
existing and planned new access road alignment;
7/ Expected spud of the first well;
8/ Anticipated measurements for each well segment including casing and cementing
programs;
9/ Anticipated drilling fluid program for each well segment including the circulation
media (mud, air, foam, etc.), well logging program and a description of the logs to be
run;
10/ Anticipated casing program and cementing program;
11/ Well control methods with a description and diagram of the blowout prevention
equipment used during each phase of drilling;
12/ Anticipated depth of water table, lost circulation zones, reservoir temperature and
pressure, temperature distribution vs depth in the area and formation pressure
distribution;
13/ A plat certified by a surveyor showing the surveyed surface location and distances
from the nearest section or tract lines;
14/ General procedures and durations of well logging & testing before rig release and
after;
15/ All environmental documentations should be provided with the drilling program and
drilling plan. It should cover the planned well(s) that are outlined in those
documents. The Licensee is required to prepare/update the environmental documents
if it has not commenced within two years from the date the drilling permit to drill
was approved. Otherwise the Licensing Authority shall cancel the permit unless
prior to the expiration date, the Operator requests an extension on a
Rework/Supplementary Notice.
16/ Any other reasonable information the Licensing Authority may require.
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9. Requirements of Well Design Plan
Well design for specified well(s) should be prepared by engineers competent in
geothermal well design, and familiar with the Ethiopian Geothermal Proclamation,
Regulation, this directive and The African Union Code of Practice for Geothermal Drilling
Practices (AU, 2016), and shall/may be reviewed by the Licensing Authority staff or peer
reviewed by an appropriately qualified and experienced person. The well design plan
includes but not limited to:-
1/ The expected geological formation, anticipated subsurface conditions like
temperature versus depth, pressure Vs depth and subsurface rock type;
2/ The casing program which includes casing design, the diameter and depth of the
borehole, casing diameters and weight, type of connections and steel grade;
3/ Engineering study and design which includes pore and fracture pressure profiles,
temperature profiles, casing & cement design, drilling fluids, hydraulic and hole
cleaning, torque and drag trajectory and well abandonment and completion design.
4/ Anticipated interval of lost circulation and problem zones;
5/ Targeted well depth and well location;
6/ Any other reasonable information the Licensing Authority may require.
10. Application for Drilling Temperature Gradient Well (TGW)
1/ A Licensee or Operator shall submit to the Licensing Authority for approval a
written program to drill a shallow well or wells for temperature-gradient purposes. In
order to qualify under this section, a program shall not contain more than 25 wells
and the maximum total depth of each of these wells shall not exceed 200 meters.
However, the licensing Authority may increase the depth if the Licensee justifies that
deeper wells are necessary to measure reliable temperature gradients.
2/ The drilling application program submitted for a Temperature Gradient Well
approval shall include well designation, well locations and elevations and geological,
geophysical and other data, including any known or inferred temperature data to
demonstrate the expected depth to the top of the reservoir. The data must provide
detail geological information and an interpretation of the data that supports the
operator’s estimation of the depth to the top of the geothermal reservoir.
3/ The Licensing Authority may require temperature monitoring and reporting, possibly
combined with pressure monitoring, so that the Licensing Authority can determine
when the drilling activity nears direct contact with the reservoir and will require that
drilling operations cease when contact with the geothermal reservoir occurs or is
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deemed imminent.
4/ The Licensing Authority may impose monitoring requirements that reflect local
drilling practices and expected characteristics of the geothermal resources that may
be present in the area described in the operator’s Drilling Permit. Other restrictions
may include increasing the technical capabilities of the proposed drilling equipment
to control pressures and the disclosure of temperature and other data that may
indicate that the reservoir is near.
5/ The Licensing Authority may oblige the immediate transmission of logging results to
the Licensing Authority for evaluation. During the intended monitoring activity, the
Licensing Authority supervisor may be present full time at the site.
11. Supplementary Notice
If there is any change in the original drilling permit or modification of the original
program might be necessary while drilling operations is on-going because of unexpected
conditions or operating needs, since the operator cannot wait with the highly expensive
drilling rig on site for the Licensing Authority processing of its notice, the changes should
be communicated but the work can continue while the licensing authority evaluate and
approve the notice. The licensing Authority may stop if it is not satisfied on the notice at
any point and require the operator for more justification.
12. Workover Permit
1/ If the Operator plans to deepen, re-drill, expand, plug and abandon, or perform any
operation that will permanently alter the original well casing program, a Workover
Permit application must be filed to the Licensing Authority accompanied by the
prescribed fee.
2/ After the Licensing Authority granted the permit on a Workover drilling operation, if
the operation has not commenced within one year from the date the permit, the
Licensing Authority shall cancel the permit unless, prior to the expiration date, and
the Operator requests a time extension on a Workover. The Licensing Authority may
extend this time limit at its discretion.
13. Application to Convert to Injection
An Operator or a Licensee planning to convert an existing well to an injection or disposal
well during the field operation phase:-
1/ If application is filled during the field exploitation phase, even if there will be no
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change in mechanical condition, it must file an application to the Licensing
Authority and it must be approved before injection is commenced.
2/ If the application is filled during the testing phase associated to drilling exploration
projects, as brine cannot be discharged on the surface and need to be reinjected,
some of the wells may be used as temporary reinjection well during the limited
testing phase while the application is processed by the Licensing Authority.
14. Review and Approval of Application
Written approval of the Licensing Authority is required prior to commencing deepening,
re-drilling, or plugging and abandonment operations. The written approval shall list any
and all requirements of the Licensing Authority. In an emergency, the Licensing Authority
may give verbal and email approval to the operator to start the stated operations covered by
this directive, provided the Licensee sends the Licensing Authority a written application of
the emergency operations conducted within 5 days after receiving the verbal and email
approval. The Licensing Authority may issue conditional approvals based on Operator
performing works they may deem necessary to be completed prior to issuing the final
permit. The Licensing Authority supervisor may grant approval for the Operator to build
necessary infrastructure such as access roads and well sites while waiting on final approval.
PART THREE
GRADE ONE GEOTHERMAL DRILLING WELL DESIGN
15. Subsurface Condition
Prior to the well design, an assessment shall be made of the subsurface conditions
anticipated throughout the well path. To do this, use information from nearby wells if
available and from relevant scientific and engineering appraisals.
1/ Exploratory wells Subsurface Conditions
In exploratory wells, sometimes temperature and pressure profiles versus depth
cannot be inferred using data from nearby wells or from surface investigations. In this
case, information to be used for well design shall be determined as follows:
a) Unless there is a suspicion of artesian conditions, subsurface fluid pressures
shall be the hydrostatic values for a column of cold water below the general
groundwater level of the area. If the groundwater hydrology, local topography,
or natural thermal features suggest artesian conditions, design fluid pressures
shall be increased to the extent implied by such indications; and
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b) Subsurface temperature values shall be assumed and follow saturation
assumption in combination with consideration of the available geosciences data
that can indicate subsurface temperatures and depth to top of reservoir or a
column of boiling water below the same level defined by sub-article (a).
2/ Production Wells Subsurface Conditions
The assessment should include expected temperatures and pressures, thermodynamic
conditions, fluid compositions as well as the relevant geological information as listed
below :
a) Lithology of geological formations including the location of any specific
stratigraphic marker beds;
b) Intensity and nature of rock alteration;
c) Compressive strength, or at least the degree of rock consolidation;
d) Faulting, fracturing and gross permeability;
e) Potential for unstable formations, such as unconsolidated breccias or volcano-
sedimentary sequences, or lithologies that might contain water-sensitive
swelling clays;
f) Fracture pressures obtained from Formation Leak–off Test (FLOT) on nearby
wells or from similar formations, or evaluated according to industry practices.
16. Casing Requirement
All wells shall be cased in such a manner as to protect or minimize damage to the
environment, ground waters and surface waters if any, geothermal resources, life, health
and property. Well casing design should incorporate mainly the intended purpose, the
design lifetime, ongoing operation and maintenance and the nature of the resource (liquid
brine, vapor, or combination), and whether the well is a flowing well or a pumped well.
The permanent wellhead completion equipment shall be attached to the anchor casing.
Division specifications for casing strings shall be determined on a well-to-well basis. All
casing strings reaching the surface shall provide adequate anchorage for blowout-
prevention equipment (BOP), hole pressure control, and protection for all-natural
resources. The following casing requirements are general but should be used as guidelines
in submitting proposals to drill.
1/ Conductor Pipe
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Conductor pipe shall be cemented with sufficient cement to fill the annular space
from the shoe to the surface.
2/ Surface Casing
Surface casing shall provide for control of formation fluids, for protection of shallow
usable groundwater, and for adequate anchorage for blowout prevention equipment.
The surface casing shall be cemented with sufficient cement to fill the annular space
from the shoe to the surface. The surface casing shall not be used as production
casing unless otherwise authorized by the Licensing Authority supervisor to meet
special well conditions. The following requirements may be modified or waived by
the Licensing Authority if justification in writing document is submitted for approval.
a) Length of Surface Casing
(1) In areas where subsurface geological conditions are variable or unknown,
surface casing in general shall be set at a depth equal to or exceeding 10
percent of the next cementing shoe depth or the depth determined by the
Licensing Authority depending on the actual well conditions. The surface
casing depth selection procedure must be designed to avoid underground
blowouts so that chosen depth that can competently withstand the
pressures of reasonable kick conditions.
(2) In areas of known high formation pressure (high temperatures at shallow
depth, or because of pressure exceeding the hydrostatic gradient), if the
surface casing (CSG) profile is judged by the Licensing Authority not to
be adequate it will be rejected or modification will be required.
(3) Within the boundaries of designated geothermal fields, the depth at which
surface casing shall be approved by the Licensing Authority on the basis
of known field conditions.
b) Cementing Point for Surface Casing
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Surface casing shall be cemented through sufficient series of low permeability,
competent lithologic units to ensure a solid anchor for blowout prevention
equipment and to protect usable groundwater and surface water from
contamination. A second string of surface casing may be required if the first
string of surface casing has not been cemented through a sufficient series of low
permeability, competent lithologic units, and either a rapidly increasing thermal
gradient or rapidly increasing formation pressures are encountered.
3/ Intermediate Casing
Intermediate casing shall be required for protection against anomalous pressure
zones, uncased fresh water aquifers, cave-ins, and washouts, abnormal temperature
zones, rapidly increasing thermal gradients, uncontrollable lost circulation zones or
other drilling hazards. Intermediate casing strings shall be cemented solid to the
surface.
4/ Production Casing
Production casing may be set above or through the producing or injection zone and
cemented above the objective zones. Sufficient cement shall be used to exclude
overlying formation fluids from the zone, to segregate zones, and to prevent
movement of fluids behind the casing into zones that contain usable groundwater.
Production casing shall either be cemented with sufficient cement to fill the annular
space from the shoe to the surface or lapped into intermediate casing, if run as a
production liner. This cement shall be a high-temperature-resistant cement.
Production liner lapped into an intermediate string shall overlap at least 50 meters;
the lap shall be cemented solidly; and shall be pressure-tested to ensure its integrity.
Cold water is recommended as the testing fluid. Pressure declines of 10% or less in
10 minutes shall be considered satisfactory.
5/ Perforated/slotted Linear
Perforated/slotted linear shall be installed across the open hole to protect the wellbore
from collapse due to unstable rock formation, pressure drawdown, or erosive effect of
fluid flow. The design of the casing shall include but not limited to: fluid property,
pressure, and temperature change that occur at any time during drilling and operation
of the well.
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17. Review and Modification of Well Design During Drilling
During well construction, the well design shall be reviewed for safety and modified if any
of the following conditions are encountered during drilling:
1/ Downhole fluid conditions such as temperature, pressure or gas that may create
pressures greater than the Maximum Design Pressure as calculated for the initial
well design.
2/ Downhole formation conditions such as faults or weak formations that may indicate
the Effective Containment Pressure is less than the values used for the initial well
design; and
3/ Casing setting depths are materially changed from the depths used for the well
design (for instance, if a casing hangs up and must be cemented shallower than the
design depth).
4/ If significant loss of the drilling fluids is encountered and could not be passed by
cementing, the zone may be cased, even though it may not be in the original casing
program.
PART FOUR
GEOTHERMAL WELL SITE SELECTION AND PREPARATION
18. Notice to the Public
The Licensing Authority may notify a well field site to public if it is needed. The public
shall have free and unrestricted access to geothermal license area, excepting however,
where restrictions are necessary to protect public health and safety or where such public
access would unduly interfere with the Licensee's operations or the security thereof. The
Licensee shall provide warning signs, fencing, flagment, barricades, or other safety
measures deemed necessary by the Supervisor to protect the public, wildlife, and livestock
from hazardous geothermal or related activities.
19. Well Site Access
Roads, bridges, and culverts shall be provided and maintained to enable continuous access
to the site for the drilling rig and associated equipment at all times during the drilling of the
well.
1/ Following well completion, and until the well is abandoned, site access shall be
maintained to a standard that:-
a) Allows safe access for normal well logging and maintenance activities by light
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vehicles; and
b) Can be readily reinstated to a condition allowing for the access of a rig or other
equipment to work over the well
2/ The site shall be designed and constructed to:
a) Support all loads imposed by the drilling rig and associated equipment and
vehicles (such as cranes);
b) Control run-off and contain drilling fluids during drilling operations;
c) Review the geotechnical assessment during site preparation and carry out
additional remedial work as required;
d) Consider consolidation grouting, where subsurface conditions warrant;
e) Have finished grades in the site area covered by the drilling rig within
tolerances specified in the rig equipment Original Equipment Manufacturer
(OEM) documentation. Outside this area, the surface of the site should be
finished to grades that provide controlled drainage.
20. Unstable Terrain
If the construction of drilling sites, roads, sumps, steam transmission lines, and other
construction attendant to geothermal operations could cause or could be affected by
slumping, landslides, or unstable earth conditions, the Licensing Authority shall require
that the Licensee submits a written analysis of the proposed work prior to the
commencement of any construction and prior to approving a permit to drill. At the request
of the Licensing Authority, the report shall be prepared by a civil engineer, with the
appropriate competency certificate. If slumping or land-sliding could be involved, the
requested report shall also be prepared by an engineering geologist, with the appropriate
competency certificate in Ethiopia and experienced in slope stability and related problems.
The report indicates that the work is planned in such a manner as to avoid or mitigate the
problem throughout the life of the project.
21. Compliance
Well sites and associated works shall be built and operated to comply with requirements of
the applicable environmental consents and permits of the country as well as all applicable
occupational health and safety statures.
22. Consideration for Waste Sump
1/ Consider the following when designing and using waste sumps:
a) Waste sumps are constructed to contain cuttings and liquid drilling and
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cementing wastes and all other contaminated fluids generated by the drilling
operations;
b) The sump is usually designed to allow isolation of part of the volume for
primary settlement of solids, with any necessary secondary settlement and
treatment occurring in the remaining volume. Alternatively, two separate
sumps can be used;
c) Operating procedures should ensure that the maximum fluid level in the sump
will remain below the cellar floor level;
d) The sump design and construction should ensure that there will be no erosion
or collapse of the sump walls during operations;
e) Where two waste sumps are constructed close together, the design shall prevent
leakage, erosion or collapse of the material separating the two sumps when the
upstream sump is full and the downstream sump is empty;
f) The design of the upstream sump should allow for a holding capacity of at least
five times the total volume of the solid material expected to be drilled from the
well;
g) The volume necessary to contain all drilled solids, waste mud and cement will
be determined by the following:
(1) Hole volumes – when brought to the surface, drill cuttings will occupy
approximately twice the in-situ volume downhole;
(2) Formations to be drilled – erodible formations can result in over-gauge
hole and excess cuttings.
h) Waste sump volume requirements can be reduced where:
(1) Cuttings are removed directly from the shale shaker
(2) Solids-removal equipment with the drilling rig results in drilling wastes
with a low water content and minimal mud waste;
(3) Total or heavy partial circulation losses are expected over extended
borehole sections with reduction of drilling cuttings recovery at surface.
i) Waste sumps should be periodically monitored in accordance with relevant
environment consents and permits.
23. Water Supply
The operator shall not commence drilling operations without an adequate supply of water
which shall be available to the site during all drilling operations. The quantity of water
available shall be adequate to meet maximum projected requirements for quenching,
drilling (including drilling without returns of circulation) and cementing operations; and
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equipment and infrastructure shall be placed and fully operational to provide the volume
and rate of flow needed in emergencies as well as under normal operating conditions. All
applicable statues as well as rules and regulations related to water rights of the country
shall be adhered to.
24. Storage Facility
Storage facilities for hazardous substances used in the drilling operation be designed and
operated to prevent adverse impact to human health and safety and the environment. Fuel
storage tanks shall be designed and located to minimize potential hazards and shall comply
with relevant national and/or local/regional statues and regulation.
25. Security
Appropriate security shall be maintained to allow only authorized personnel access to the
site during drilling operations.
26. Fencing and Signage
Appropriate fencing and signage shall be erected and maintained. Signage shall be located
at the site entrance advising of:-
1/ Hazards, constraints on entry, and requirements for personal protection equipment;
2/ Waste sumps that constitute hazards; and
3/ Areas where hazardous gases may be discharged or can accumulate.
4/ All signage should be posted in a local, national and English language clearly.
All safety-related signage shall include recognized international safety and hazard symbols
to ensure maximum safety for workers, local residents and visitors. Symbols for
Flammable, Crane Overhead, Danger of Suffocation, Watch for Falling Objects, Watch
Your Step, High Voltage and Hard Hat Area are among those highly suggested, along with
any other signs deemed necessary.
PART FIVE
GEOTHERMAL WELL DRILLING EQUIPMENT AND TOOLS
27. Suitability of Equipment
Equipment associated with drilling works shall be assessed for suitability and wherever
applicable, should comply with national and international standards.
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28. Mast Guy Anchor
Where the drilling rig requires the installation of mast guy line anchors in the ground
around the well site, the design and construction of these anchors shall comply with the
Original Equipment Manufacturers (OEM) documentation.
29. Rig and Hoisting Capacity
On completion of the well design all loads to be imposed from drilling operations,
including the running and cementing of casings, shall be assessed, and a margin of safety
shall be added to establish the minimum hoisting capacity required. The capacities of all
components of the equipment specified and selected for the drilling shall exceed the
minimum capacities estimated to be required to meet the loadings. Assessment of the
capacities of separate components of the drilling rig equipment will be based on
certifications be presented to the Licensing Authority.
30. Generator, Electrical Systems and Lighting
Generator capacity shall be adequate to supply the entire electrical load required by the rig
and associated equipment to be used in drilling the well. Standby generator capacity shall
also be available and be adequate to supply, at a minimum, the electrical load for Prime
movers driving the drawworks, pumps or rotary table; electrically driven air compressors;
Lighting; and Blow Out Preventer (BOP) accumulator pump.
31. Gas Detection
An appropriate gas detector system comprising at least four sensors with the capability of
detecting both hydrogen sulfide (H2S) and carbon dioxide (CO2) shall be on site and
functioning at all times while the rig is operating. Gas detectors shall be maintained in
accordance with the Original Equipment Manufacturers (OEM) documentation, and shall
activate both audible and visual alarms.
A gas hazard abatement plan shall be prepared and all rig crew and support personnel shall
be familiar with its application.
Gas hazard escape equipment shall be provided at appropriate locations and available for
use at all times when the rig is operational. All rig and support personnel shall be trained
and competent in the use of Emergency Life Support Apparatus (ELSA) or equivalent
escape equipment. At least one Self-Contained Breathing Apparatus (SCBA) shall be
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onsite, and at least two of the rig crew on every shift shall be trained and competent in its
use. There should also be at least two muster points and wind sock on the drilling rig.
32. Rig Instrumentation
1/ Minimum requirements for rig instrumentation shall be:
a) Total weight indicator;
b) Tank volume and gain-loss indicators;
c) Standpipe pressure gauge;
d) Wellhead pressure gauge; and
e) Indicators for temperatures of rig pump suction fluids and returning fluids
(drilling fluid going in and coming out of the well).
2/ Other instrumentation shall include:
a) Pump speed indicators;
b) Rotary torque indicator;
c) Drilling fluid flow rate indicator (including air flow if appropriate) for
downhole flow, return flow, or both;
d) Kelly height and rate of penetration indicators;
e) Drilling fluid density;
f) Recorders which record any or all of these parameters;
g) Rotary speed indicator; and
h) Makeup torque indicator.
Rig instrumentation shall be inspected, maintained and recalibrated as necessary at the start
of each well, and at intervals specified in the OEM standards during drilling operations.
33. Blow Out Preventer and Gas Accumulator
Blowout-Prevention (BOP) Equipment installations shall include high temperature-rated
packing units and ram rubbers, if available, and shall have a minimum working-pressure
rating equal to or greater than the lesser of:
1/ A pressure equal to the product of the depth of the Blowout Preventer (BOP) anchor
string in meters times 0.2 bar per meter;
2/ A pressure equal to the rated burst pressure of the Blowout Preventer anchor string;
3/ A pressure equal to 138 bars (13.8 megapascals).
During specific inspections and testing of the Blowout Preventer (BOP), the assigned
supervisor of the Licensing Authority or advisor shall be presented at the site.
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34. Blowout Prevention Equipment and Procedures
1/ All necessary cautions shall be taken to keep all wells under control at all times,
utilize trained and competent personnel, and utilize properly maintained equipment
and materials. Blowout preventers and related well control equipment shall be
installed, tested immediately thereafter and maintained ready for use until drilling
operations are completed.
2/ Certain components, such as packing elements and ram rubbers, shall be of high
temperature resistant material as necessary. All kill lines, blow down lines,
manifolds and fittings shall be steel made and shall have a temperature rated
minimum working pressure rating equivalent to the maximum anticipated wellhead
surface pressure.
3/ Dual control stations shall be installed with a high-pressure backup system. One
control panel shall be located at the driller’s station and the other control panel shall
be located on the ground at least 15 meters away from the wellhead.
4/ Air or other gaseous fluid drilling systems shall have blowout prevention assemblies.
Such assemblies may include, but are not limited to, a rotating head, a double ram
blowout preventer or the equivalent, a banjo-box or an approved substitute and a
blind ram blowout preventer or gate view, respectively. Exceptions to the
requirements of this section will be considered by the Licensing Authority
Supervisor only for certain geologic and well conditions such as stable surface areas
with known low subsurface formation pressures and temperatures.
5/ Before drilling below conductor pipe, at least one remotely controlled hydraulically-
operated expansion type preventer or an acceptable alternative (a diverter with a
rotating head should be installed), approved by the Licensing Authority Supervisor,
including a drilling spool with side outlets or equivalent shall be installed. A kill line
and blow down line with appropriate fittings shall be connected to the drilling spool.
This requirement may be waived by approval of the Licensing Authority Supervisor
if the operator can justify with sound engineering and geosciences judgment.
6/ Before drilling below any of Surface, Intermediate, and Production Casings, the
blowout prevention equipment shall include a minimum of:-
a) One expansion-type preventer and accumulator (Annular Preventer) or a
rotating head;
b) A Non-Return Valve (NRV) on the drilling string - to prevent inflow of
annular fluids or formation into the bottom of the drill string. NRVs should
also be used in the upper sections of the drill string to minimize the volume of
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aerated fluid to be vented from the drill string when making a connection;
c) A manual and remotely controlled hydraulically-operated double ram blowout
preventer or equivalent having a temperature rated minimum working pressure
rating which exceeds the maximum anticipated surface pressure at the
anticipated reservoir fluid temperatures;
d) A drilling spool with side outlets or equivalent;
e) A kill line equipped with at least one valve; and,
f) A blowdown line equipped with at least two valves and securely anchored at
all bends and at the end.
7/ Testing and Maintenance. Ram-type blowout preventers and auxiliary equipment
shall be tested to a minimum of 138 bars or to the working pressure of the casing or
assembly, whichever is lesser. Expansion-type blowout preventers shall be tested to
70 percent of the above testing requirements.
a) The blowout prevention equipment shall be pressure tested:
(1) Prior to spud or upon installation;
(2) Prior to drilling out plugs and/or casing shoes;
(3) Not less than once each week, alternating the control stations; and,
(4) Following repairs that require disconnecting a pressure seal in the
assembly.
b) During drilling operations, blowout prevention equipment shall be actuated to
test proper functioning as follows:
(1) Once each trip for blind and pipe rams, but not less than once each day for
pipe rams; and,
(2) At least once each week on the drill pipe for expansion-type preventers
(Annular BOP).
All flange bolts shall be inspected at least weekly and re-tightened as necessary
during drilling operations. The auxiliary control systems shall be inspected daily
to check the mechanical condition and effectiveness and to ensure personnel
acquaintance with the method of operation. Blowout prevention and auxiliary
control equipment shall be cleaned, inspected, and repaired, if necessary, prior
to installation to assure proper functioning. Blowout prevention controls shall be
plainly labeled, and all crew members shall be instructed on the function and
operation of such equipment. A blowout prevention test shall be conducted
weekly for each drilling crew. All blowout prevention tests and crew drills shall
be recorded on the driller’s log.
8/ Related Well Control Equipment. A full opening drill string safety valve in the open
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position shall be maintained on the rig floor at all times while drilling operations are
being conducted. A Kelly cock shall be installed between the Kelly and the swivel.
PART SIX
GEOTHERMAL WELL DRILLING AND TESTING
35. Competence and Supervision of Personnel
Personnel in immediate control of any drilling or workover operations shall be trained and
competent in blowout prevention and managing of geothermal wells and should be certified
by the Licensing Authority in accordance to the directive from issued or competent body
from other country presenting the necessary qualification documents and Curriculum Vitas
through the embassy and, such personnel shall be responsible for all drilling related
activities at drilling site including managing the rig, mud system, cementing equipment,
power supply while it is operational.
36. Drilling in Unstable Area
1/ Drilling any wells, including water wells, should not be drilled on the top of
manifestation like fumaroles, geysers, hot springs, mud pots (unstable areas) rather be
a safe distance away from it and applying for drilling permit for such type of areas
require to submit additional adequate information to the Licensing Authority. The
Licensing Authority determines in consultation with appropriate water law and
competent government body, after a thorough geological investigation, that drilling in
an unstable area is feasible.
2/ The Licensing Authority supervisors shall be present at the well at all times during
the initial phases of drilling until the surface casing has been cemented and the
Blowout Preventer (BOP) has been pressure-tested satisfactorily. The Licensing
Authority supervisor may observe all drilling operations at the well and if, conditions
warrant, gives essential advices to the operator.
3/ The Licensee, while drilling the surface casing hole or for any well and well section,
shall continuously monitor and record the following:
a) Drilling fluid temperature (in and out),
b) Drilling fluid pit level,
c) Drilling fluid pump volume,
d) Drilling fluid weight, and,
e) Drilling rate.
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37. Subsidence and Seismic Activity
Subsidence and seismic monitoring shall be done by the operator especially at the
exploitation phase (or may start at the exploration drilling) and continue through the
construction of power plant and production for long term monitoring of well. The operator
may collaborate with responsible government organ of the Country for collecting previous
data if available. Subsidence and seismic activity from conventional geothermal operations
are difficult to predict, particularly in the absence of detailed knowledge of the local
subsurface stress conditions, rock properties and permeability structure.
1/ Subsidence leveling surveys should be started at the exploration drilling stage by
detection and measurement using like Global Positioning System (GPS) and
interferometric synthetic aperture radar (InSAR) methods as subsidence is usually
expressed as an annual rate. The licensing authority may waive the requirement for
exploration wells depending on the availability of subsurface data.
2/ Surveys and Bench Marks
a) Subsidence benchmarks, at well sites, tied to existing first- and/or second-order
networks, are required for all wells that will be tested or produced. These
benchmarks shall be the responsibility of the licensee at its own expense.
Surveys shall precede extensive production testing of the well {which could be
located in a new prospect or in a field already under exploitation}
b) All survey work shall be identified with the GPS coordinates by Provincial
Surveyor.
c) All work shall be done under the direct supervision of a Registered Civil
Engineer or Licensed Land Surveyor.
d) An adequate series of bench marks shall be set as required by the Licensing
Authority and shall be tied to existing survey nets.
e) All field work, computations, etc., shall conform to GCS_Adindan or other
Ethiopian equivalent standards.
f) All surveys shall be second-order or better.
g) All single-point tie-ins shall be double-run. Survey loops between two points
on existing surveys may be single-run.
h) Equipment shall be equal to or better than that accepted by the GCS_Adindan
or other Ethiopian equivalent standards for second-order surveys.
i) Types of acceptable bench marks are:
(1) Brass rod driven to refusal or 10 meters and fitted with an acceptable brass
plate; and,
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(2) Permanent structure (head walls, bridges, etc.) with installed plate.
j) Bench marks at well sites shall be situated so as to minimize the possibility of
being destroyed during any subsequent work-over activity at the wells. Each
bench mark shall be well marked so as to be plainly visible to work-over
crews.
k) Between the well site and the network, bench marks shall be set at one-
kilometer intervals or as specified by the Licensing Authority.
l) Surveys shall be run annually by and at the expense of the Operator while
well(s) are being produced unless otherwise specified by the Licensing
Authority.
m) The adjusted data from all surveys shall be submitted to the Licensing
Authority within 60 days after leveling is completed.
n) Resurveys of the first- and second-order networks shall be coordinated by the
Licensing Authority.
3/ Reservoir Monitoring Engineering.
a) Initial bottom-hole pressures and temperatures (allowing a minimum of one-
month shut-in time or until stable conditions are recorded) shall be submitted to
the Licensing Authority within thirty (30) days of completion of work.
b) All preliminary test data shall be submitted to the Licensing Authority within
thirty (30) days of completion of drilling work.
38. Drilling Fluid
The properties, use, and testing of drilling fluids and the conduct of related drilling
procedures shall be such as are necessary to prevent the blowout of any well, or the
uncontrolled flow of fluid from any well. Sufficient drilling fluid materials to ensure well
control shall be maintained in the field area and readily accessible for immediate use at all
times.
1/ Drilling Fluid Return Temperatures
The temperature of the return drilling fluid shall be monitored continuously during
the drilling of any boreholes section. Either a continuous temperature monitoring
device shall be installed and maintained in working condition, or the temperature
shall be read manually. In either case, return drilling fluid temperatures shall be
entered into the log book after each joint of pipe has been drilled down every 10
meters.
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2/ Drilling Fluid Control
Before pulling the drill pipes, the drilling fluid shall be properly conditioned or
displaced. The hole shall be kept reasonably full at all times. Mud cooling techniques
shall be utilized when necessary to maintain mud characteristics for proper well
control and hole conditioning.
3/ Drilling Fluid Testing
Mud testing and treatment consistent with good operating practice shall be performed
daily or more frequently as conditions warrant. Mud testing equipment shall be
maintained on the drilling rig at all times. The following drilling fluid system
monitoring or recording devices shall be installed and operated continuously during
drilling operations, with mud, occurring below the shoe of the conductor casing:
a) High-low level mud pit indicator including a visual and audio-warning device,
if applicable.
b) De-gasers, de-silters, and de-sanders.
c) A mechanical, electrical, or manual surface drilling fluid temperature
monitoring device. The temperature of the drilling fluid going into and coming
out of the hole shall be monitored, read, and recorded on the driller’s or mud
log for a minimum of every 10 meters of hole drilled below the conductor pipe.
d) A hydrogen sulfide indicator and alarm shall be installed in areas suspected or
known to contain hydrogen sulfide gas which may reach levels considered to
be dangerous to the health and safety of personnel in the area.
4/ Monitoring
For surveillance purposes, from the time drilling operations are initiated and until the
well is completed or abandoned, personnel(s) of the drilling crew shall monitor on the
rig floor at all times unless or until the well is secured with blowout preventers or
cement plugs.
39. Geothermal Wastes and Refuse
1/ Wastes and refuse attendant to geothermal operations, including but not limited to
water, oil, chemicals, mud, and cement, shall be disposed of in such a manner as not
to cause damage to life, health, property, freshwater aquifers or surface waters, or
natural resources, or be a menace to public safety. Disposal sites for geothermal
wastes shall also conform to the Laws of Federal Democratic Republic of Ethiopia.
2/ Dumping harmful chemicals where subsequent meteoric waters might wash
significant quantities into freshwaters shall be prohibited.
3/ Drilling mud shall not be permanently disposed of into open pits. Cement slurry or
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dry cement shall not be disposed of on the surface. Unused equipment and scrap
attendant to geothermal operations shall be removed from a production or injection
operations site and/or stored in such a manner as to not cause damage to life, health,
or property, or become a public nuisance or a menace to public safety. Trash and
other solid waste materials attendant to for geothermal operations shall be removed
and disposed consistent with applicable laws and regulations.
4/ Use of hazardous chemicals shall be minimized. If such chemicals are used, their
transport, handling and disposal shall be in conformity with the laws of Ethiopia and
international environmental standards.
40. Directional Drilling
On completion of the well, the casing condition shall be monitored for any damage,
where:-
1/ The kick-off point and interval of hole where the hole angle is built up are inside
casing; kick off can be in open hole too and
2/ The section of hole below the casing subjects the casing to potential wear from
subsequent drilling.
Any indicated casing damage shall be assessed. If it is likely to diminish the safety or
integrity of the well then it shall be repaired.
41. Installation, Testing and Inspection of Permanent Wellhead and BOP
All permanent wellhead components shall be pressure tested prior to installation on the
well. Where possible, pre-assembled components should also be pressure tested as an
assembled unit prior to installation.
42. Security of Wellhead Valve
Upon completion of works, the wellhead equipment shall be secured against operation by
unauthorized personnel.
43. Specified Operating Range
Following well completion and before the well is put in service, the range of conditions
under which the well can be safely operated shall be specified and documented. This
specified operating range shall be reviewed throughout the lifetime of the well to ensure it
reflects any changes in reservoir or well condition.
44. Post Well Stimulation (Acidification, Thermal Fracturation, Hydraulic Fracturation)
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Within 60 days after the cessation of a well stimulation treatment, the Operator shall
submit a report to the Licensing Authority describing:
1/ The pressures (downhole or wellhead pressures) recorded during monitoring and the
well stimulation treatment;
2/ The pressures recorded during the first 30 days of production pressure monitoring;
3/ The date and time that each stage of the well stimulation treatment was performed;
4/ How the actual well stimulation treatment differs from what was anticipated in the
well stimulation treatment design;
5/ How the actual location of the well stimulation treatment differs from what was
indicated in the permit application; and,
6/ A description of hazardous wastes generated during the well stimulation activities
and their disposal, including copies of all hazardous waste manifests used to
transport the hazardous wastes offsite to an authorized facility.
45. Hydraulic Fracturing Operation
While conducting stimulation work on wells, especially for hydraulic fracturing, the
following procedures should be followed by the licensee
1/ A Licensee must not conduct a hydraulic fracturing operation at depth less than 600
m below ground level.
2/ During fracturing, injection or disposal operations on a well, a well authorization
holder must immediately report to the Licensing Authority any seismic event within
a 3km radius of the drilling pad that is recorded by the well permit holder or reported
to the well permit holder by any source available if;
a) The seismic event has a magnitude of 2.5 or greater, or
b) A ground motion is felt on the surface by any individual within the 3 km radius
of the drilling pad.
3/ If a well is identified by the well permit holder or the Licensing Authority as being
responsible for a seismic event under Article 1, must suspend fracturing, injection
and disposal operation on the well immediately.
4/ Fracturing and disposal operation suspended under Article 2 may continue once the
well permit holder has implemented operational changes satisfactory to the
Licensing Authority to reduce or eliminate the initiation of additional induced
seismic events.
PART SEVEN
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GEOTHERMAL WELL OPERATION AND MAINTENANCE
46. Well Completion
1/ A well is considered to be completed after drilling operations have ceased and a well
completion testing is conducted and the well is judged to be capable of producing a
geothermal resource, or idle, or plugged and abandoned after the 30 days.
2/ A well completion report shall be submitted to the Licensing Authority thirteen (30)
days after the well completion.
47. Well Integrity Monitoring Plans
A Well Integrity Monitoring Plan can cover multiple wells or even reservoirs. Where this is
the case:
1/ The scope of the Well Integrity Monitoring Plan shall be stated, along with any
individual wells or groups of wells that are specifically excluded from that plan; and
copies forwarded to the Licensing Authority.
2/ Processes shall be put in place to record any variation to the Well Integrity
Monitoring Plan for individual wells or groups of wells.
3/ The Well Integrity Monitoring Plan shall be designed to indicate the presence of any
of the following defects or impairments:
a) External, near surface, corrosion or leakage of the anchor casing; any corrosion
leakage of the wellhead components; broken or perforated casing and failed
casing connections;
b) Leaks into or out of the casing;
c) Buckled or distorted casing;
d) Collapsed casing and corroded casing;
e) Annular flow outside the casings; and
f) Chemical deposition or scale.
4/ The Well Integrity Monitoring Plan shall provide for observation of the following
types of change, all of which can be observed at the surface:
a) Changes in discharged fluid chemistry, enthalpy, pressures or flow rates of
production wells not explained by normal expected evolution of well discharge
conditions;
b) Changes in surface manifestations of geothermal flow, and particularly the
development of new hot areas on or near the well site;
c) Any indication of fluids entering into a cemented casing annulus at surface and
any deterioration of that cement near surface;
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d) Alternatively, any variation in flow from casing annuli; and
e) Loss of pressure measured at a side valve when the well is otherwise known to
be under pressure.
48. Wellhead Inspection and Maintenance
In addition to the Well Integrity Monitoring Plan, or alternatively, as part of it, each
wellhead shall have a documented annual inspection, and at least the following information
shall be recorded by the well owner and copies forwarded to the Licensing Authority.
1/ Wellhaed Pressure and Temperature;
2/ Well Status like shut-in, bleed, production and injection;
3/ Operating condition of wellhead valves;
4/ Leakage from valve gate or valve stem seals;
5/ Condition of protective paint systems;
6/ Condition of the anchor casing;
7/ Condition of the site and cellar drainage; and
8/ Changes in the vertical position of the wellhead measured relative to other casings
and to the cellar and the position of the CHF measured relative to the cellar datum.
49. Well Tests and Remedial Works
1/ The Licensing Authority Supervisor shall require such tests or remedial works as in
his judgment are necessary to prevent damage to life, health, property and natural
resources; to protect geothermal reservoirs from damage or to prevent the infiltration
of detrimental substances into underground or surface water.
2/ This type of tests shall be conducted:-.
a) Casing Tests includes spinner surveys, wall thickness, pressure and radioactive
tracer surveys.
b) Cementing Tests includes cementing of casing, pumping of plugs, hardness of
plugs and depth of plugs.
c) Equipment Tests includes gauges, thermometers, surface facilities, lines, and
vessels and blowout-prevention equipment.
d) BOP inspections and/or tests are normally performed on all drilling wells.
3/ Any remedial works identified by the inspection program shall be completed as soon
as practicable. Where there is a potential for further deterioration that threatens
personnel safety, immediate steps shall be taken to eliminate that risk or to reduce
the risk of harm to a level as low as is reasonably practicable.
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50. Suspended Wells
When a well is suspended for longer time before the production casing has been run, the
following applies:-
1/ The cement plug should be placed on a bridge plug or packer located at or near the
production casing shoe and not less than 10 m above the top of any liner;
2/ The cement plug should also be placed in a manner that minimizes dilution of the
cement slurry by fluids in the well;
3/ The cement materials should be selected to withstand ambient fluids and
temperatures, and to develop a limited compressive strength to avoid casing damage
when the cement is subsequently drilled out;
4/ The casing above the sound cement should be filled to the surface with a weak
bentonite and cement type of filler; and
5/ The cement plug shall be pressure tested to a sufficient test pressure and duration to
confirm the cement plug is sound and provides sufficient integrity for the duration of
the well suspension.
PART EIGHT
51. Injection Well
1/ For injection well, new wells may be drilled and/or old wells may be converted for
water injection or disposal service. An Operator planning to convert an existing well
to an injection or disposal well, even if there will be no change in mechanical
condition, must file a Workover /Supplementary Notice with the Licensing Authority
and the Licensing Authority must approve the notice before injection is commenced.
Injection wells shall conform to the licensing Authority spacing regulation and
African Union Code of Practice.
2/ The spent reservoir fluids shall be re-injected, provided that they will not impair
groundwater resources. On the other hand, injection of water from other sources
shall be allowed, provided that it will not impair groundwater or surface water
resources and is compatible with the availability of water resources in the area.
3/ Fluids like harmful wastes such as solutions contaminated by organic compounds or
radioactive species cannot be injected in the subsurface in accordance with other
applicable laws of the country.
52. Injection During Exploration/Short Term Injection
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The Licensing Authority should approve short term injection operations application as fast
as possible during an exploration drilling project with the following requirements if it was
not included in the approved drilling program:-
1. Letter setting forth the entire plan of operations, which should include:
a) Reservoir conditions;
b) Method of injection can be rig on injection or in the well through casing, tubing,
or tubing with a packer;
c) Source of injection fluid; and,
d) Estimates of daily amount of water to be injected.
2. Map showing contours on a geologic marker at or near the intended zone of injection.
3. One or more cross sections showing the wells involved.
4. Analyses of fluid to be injected and of fluid from intended zone of injection.
5. Copies of letter or notification sent to neighboring operators.
53. Injection Approval
A written approval of a project will be sent to the Operator and such approval will contain
those provisions specified by the Licensing Authority as necessary for safe operations as
fast as possible. Injection shall not commence until approval has been obtained from the
Licensing Authority.
54. Surveillance for Injection Work
1/ Surveillance of waste water disposal or injection projects is necessary on a
continuing basis to establish to the satisfaction of the Licensing Authority Supervisor
that all water is confined to the intended zone of injection.
2/ When an Operator proposes to drill an injection well, convert a producing or idle
well to an injection well, or workover an injection well and return it to injection
service, the Operator shall be required to demonstrate complete casing integrity to
the Licensing Authority by means of a specific test.
3/ To establish the integrity of the casing and the annular cement above the shoe of the
casing, within 30 days after injection is started into a well, the Operator shall make
sufficient surveys to demonstrate that all the injected fluid is confined to the intended
zone of injection. Thereafter, such surveys shall be made at least every two years or
more often if ordered by the Supervisor. All such surveys shall be witnessed by an
engineer.
4/ After the well has been placed on injection, the Supervisor shall visit the well site
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periodically. At these times, surface conditions shall be noted and, if any
unsatisfactory conditions exist, the Operator shall be notified of required remedial
work. If this required work is not performed within 90 days, the approval issued by
the Licensing Authority shall be rescinded. The Supervisor may order that the repair
work be done immediately if it is determined that damage is occurring at a rapid rate.
5/ Injection pressures shall be recorded and compared with the pressures reported on
the monthly injection reports. Any discrepancies shall be rectified immediately by
the Operator. A graph of pressures and rates versus time shall be maintained by the
Operator. Reasons for anomalies shall be promptly ascertained. If these reasons are
such that it appears damage is being done, approval by the Licensing Authority may
be rescinded, and injection shall cease.
6/ When an injection well has been idle for two years, the Licensing Authority may
inform the Operator, by letter, that approval for use of the well for injection purposes
is rescinded. If the Operator intends to reclaim the well for injection purposes, a
Rework/Supplementary Notice shall be filed proposing to demonstrate by specified
tests that the injected fluid will be confined to the intended zone of injection.
PART NINE
GEOTHERMAL WELL PLUGGING AND ABANDONMENT.
55. Plugging Requirements for a Well
To block inter-zonal migration of fluids in wells that shall be abandoned, a licensee must
plug a well in a manner that ensure the following :
1/ Protect life, health, environment, and property
2/ Prevent contamination of the fresh waters or other natural resources
3/ Prevent contamination of ground waters
4/ Prevent damage to geothermal reservoirs and its integrity
56. Purpose and Requirements for Abandonment
The Licensing Authority may require the following general requirements of field
operations for well abandonment:-
1/ Any well that the Licensee does not intend to use or that is no longer active shall be
properly decommissioned by the Licensee.
2/ Notice to plug and abandon Geothermal Resources Well is required for all wells.
3/ History of Geothermal Resources Well shall be filed within 60 days after completion
32
of the plugging and abandonment.
4/ Well Plugging and Abandonment report submitted to the Licensing Authority will
not be approved until all records have been filed and the site inspected for final
clean-up by Licensing Authority Supervisor.
5/ Subsequent to the plugging and abandonment of the hole, all casings shall be cut off
at least 2 meters below the surface of the ground. All concrete cellars and other
structures shall be removed, and the surface location restored, as near as practicable,
to original conditions when all the wells of the cluster are abandoned.
6/ Good quality, heavy drilling fluid approved by the Licensing Authority Supervisor
shall be used to replace any water or geothermal fluids in the hole and to fill all
portions of the hole not plugged with cement.
7/ All cement plugs, with the possible exception of the surface plug, shall be pumped
into the hole through drill pipe or tubing.
8/ All open annuli shall be filled solid with cement to the surface.
57. Amendment
This Directive shall be periodically amended based on the procedures to be issued by EEA
to reflect the latest developments in grade one geothermal resource development drilling
implementation and related regulations.
58. Effective Date
This Directive shall come into force from the date of approved by the board as of -----------
------------------- 2021
………………………………..
FREHIWOT WELDEHANNA (PhD)
BOARD CHAIRMAN, ETHIOPIAN ENERGY AUTHORITY