© drops technology as integration of 3d-shared earth model with drops drilling simulator to reduce...

© Drops Technology AS

Integration of 3D-shared earth model with Drops Drilling

Simulator to reduce drilling costs

NFR project 150496/210 Presented in Stavanger 4 April 2003

Presented by Runar Nygård, Drops Technology AS


Outline of presentation

Project description What is drilling optimization? DDS – Drops Drilling Simulator-Technical description Results so far Summary


Project participants

Drops Technology AS Drops Technology AS was founded in 1997. It is a limited

company incorporated in Oslo, Norway DROPS Technology AS sells services, program licenses

and user access, based on DROPS’ drilling optimization simulator DDS 2.7

PGS-Tigress PGS-Tigress is 100% subsidiary of PGS PGS-Tigress is a software company for the Exploration

and Production professionals with a suite of integrated tools

The main product being TIGRESS (The Integrated Geoscience and Reservoir Engineering Software System).


Project description Today the Drops Drilling Simulator needs drilling data as

reference to build the physical drillability needed for the simulator to simulate drilling.

This project will extend the drilling simulation capabilities so other data from logs and seismic attributes from a shared 3D earth model can be used as basis for drilling simulations.

Using such information would also give better prediction of drillability variations related to different well paths.

GOALS Implement DDS in Tigress shared earth model software Develop new models for drillability based on other type of

data than drilling data Develop automatic well planning routine in Drops Drilling

simulator


Tigress

Integrated software for all disciplines in petroleum exploration

PC version is Linux based

Powerful database (PDR)

Open link to other software (data loading)


Drilling optimization:Simulation tools

Today’s oil and gas industry utilize simulators mainly in three of the four main operational engineering disciplines

Reservoir, production and formation evaluation all use simulation tools to better evaluate different scenarios and to improve interpolation and economics

In advance the production, reservoir and seismic/log analysis can be performed

Drilling Engineering has a lack in planning tools available for the actual drilling process

Drilling software is mainly related to the fluid system and well-rock interaction (well integrity)


The Learning Curve has been slow and expensive.

Drilling optimization: Learning Curve

Even after 30-40 wells have been drilled in the same formations in a field there are still many combinations of bits and operating conditions that have not been tried

Therefore you might not have reached the lowest drilling cost

Utilizing a simulator that can simulate these combinations in a short period of time after the first well has been drilled, is definitely a strong tool


Drilling optimization: Cost equation

Footage

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Required inputs are actual bit costs, rig rate, and other costs

The simulator calculates rotating time (from ROP), connection time and trip time

The individual bit run cost pr. meter and the cumulative cost pr. meter are used to evaluate the optimum in terms of economics

Other costs, like: MWD/LWD, DD, down hole equipment, fluids, personnel, boats and other


The Drilling Optimization Simulator

simple overview An earlier drilled well well is the referenceThe simulator iterate a perfect match from the reference “drillbehind”. Output from this is a strength log, ARSL

This strength log is used as basis for the next well

Adjusted for lithology (formation thickness) and survey, the new well can be optimized


Technical Approach

Predictive ROP models have been developed in the past two decadesROP models exist for Rollercone, PDC and NDB/Geoset bitsDescribe the physical interaction between the bit and the rock as a

function of the parameters that effect the bit performance. Different bits have different cutting mechanisms.The cutting mechanism is integrated over the entire bit face and

converted to ROP in meter/hr.As the bit penetrates through the different formations the bit wears,

which again effect the ROP.The ROP models use unconfined rock strength as an inputThe ROP models can be used to predict unconfined rock strength if

ROP is known. The models have been verified in the laboratory and field

ROP

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Apparent Rock Strength Log (ARSL) Creation Procedure

Each Bit-/BHA run is treated separately Simulations are performed for each bit with

different ROP models dependent on bit type “Apparent rock strength” is calculated based

on an initially assumed bit wear coefficient A new wear coefficient is then estimated and a

multiple solutions iteration procedure for the entire bit run is performed until the calculated bit wear equals the actual bit wear

The resulting “apparent rock strength” log is now specific for the formations in this area


DROPS Drilling Optimization Simulator

DROPS Drilling S im ulator Functionality

$ /ftC u m . $ /ft

F lo w ra teM u d W t.

R h e o lo gy

W O BR P MJe ts

O p e ra tingP a ra m e te rs

B it T ypeT rico ne

P D CN D B

B it D e s ignB it W e ar# C utte rs

C u tte r In fo .

B itP a ra m e te rs

A R S LR o ck S t.P o re P r.S u rvey

R o ck D B .A b ra sive n .% L itho lo gy

F o rm a tionM o d e l

D R O P S D rillin g S im u la to rR O P

O p tim umD rillin g - $


Needed input data for ARSL creation

Drilling, mudlogger and bit data needed Drilling data - Depth, ROP, WOB, RPM, Flowrate,

Plastic Viscosity, Mud Weight Mudlogger data - Formation thickness Percent

lithologies, Pore Pressure Bit Data- Size, Type, Jets, Number of cutters and

blades, Backrake, Siderake, PDC layer thickness, Backup Cutters Info., Depth In, Depth Out, Wear In, Wear Out, TFA and POA.


Drops Drilling Simulator DDS

Currently used in planning, follow up and post analysis of wells DDS is a Windows based application and the interface is

user friendly, just “point and click”


Drops Drilling Simulator DDS

Control sheet window Cost is re-calculated based on every simulated change


Existing drilling data is used to calculate a ARSL (Apparent Rock Strength Log)

The ARSL is used to plan and simulate the forthcoming wells in the field

Assumption is that the drillability properties for each formation does not change from well to well

The simulator does not take into consideration any 3D-effects like anisotropy in stress field or mechanical data

Up to now there has been time consuming to simulate numerous different well trajectories

Drops Drilling Simulator: The ARSL

700

800

900

1000

1100

1200

1300

1400

1500

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1700

1800

1900

2000

2100

0 10 20 30 40 50 60

Apparent Rock Strength

De

pth

[m

TV

D]

Well A

Well B

Well C


Learning Curve for One Bit

Learning Curve for 12.25 Section Using One Bit.

800000

900000

1000000

1100000

1200000

1300000

1400000

1500000

1600000

1700000

1800000

0 10 20 30 40 50 60 70 80 90 100110

120130

140 150160

170180

190

Number of Simulations.

To

tal

Co

st

for

12

.25

Se

cti

on

, $

Bit A Bit B Bit C Bit D. Bit E


Learning Curve Multiple Bits

Learning Curve for 12.25 Section Using Multiple Bits.

800000

900000

1000000

1100000

1200000

1300000

1400000

1500000

0 20 40 60 80 100 120 140 160 180 200Number of Simulations.

To

tal

Co

st

for

12

.25

Sec

tio

n,

$

Bit A

B

it B

Bit A

B

it A

Bit B

Bit A

Bit D

Bit A

2 X B

it D

Bit D

Bit C

Bit C

Bit D

Bit C

Bit A

Bit B

B

it E

Bit B

Bit C

Bit C

B

it D

Bit D

Bit B


Simulator results: ROP

0

5

10

15

20

25

30

35

40

45

50

3650 3700 3750 3800 3850 3900 3950 4000

Depth, mTVD

RO

P,

m/h

.

Measured ROP

Calculated ROP

Measured and Calculated ROP vs depth


Simulator Results: Rotating Hours

Cumulative rotating time for 12.25 inch Lyng bit

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

2800 3000 3200 3400 3600 3800

TVD (m)

Cu

mu

lati

ve r

ota

tin

g t

ime

(ho

urs

)

. Measured rotating time

Calculated rotating time


Simulation of Bit wear

Bit Wear Evaluation

0

1

2

3

4

5

6

7

8

2854 3000 3050 3100 3150 3200 3250 3300 3350 3400 3450 3500 3550 3600 3650 3688

TVD (m)

Bit

Wea

r

.

Center

Gage

Average

(Reported Wear 2-6)


In addition to being a planning tool, DDS has functionality for comparing the planned well program with the actual data from the rig

Conduct rapidly decisions in unforeseen situations

Re-simulate the planned program with new equipment, bits, etc.

Time Progress, 12.25" Section

2050

2100

2150

2200

2250

2300

2350

2400

2450

2500

2550

2600

2650

2700

2750

2800

2850

2900

0 5 10 15 20 25 30

Time [Hr]D

epth

[m

MD

]

Rotating Time, Simulated

Rotating Time, Field

Drops Drilling Simulator: Real time Follow up


Software integration

Task 1 Implement DDS in Tigress shared earth model software This has been done by running Drops using vm-ware in

Linux All data needed for running DDS is stored in PDS. Vector based special bit information is implemented in

Tigress as an drilling event Adjusting data for DDS based on new well trajectories is

easily done in Tigress by using their G&G modules DDS 2.7 is now commercially for sale by Tigress

This task of the project is finished as planned


Results: Software integration


Software integration


ARSL based on other strength criteria

When bit is penetrating the rock, different modes of failure occurs in the rock like, shearing, crushing and tension fracturing

The drillability is the resistance of the rock being penetrated by the drill bits

Drillability of the rock is a dynamic parameter However, Rock strength and drillability are closely

connected In this ongoing work we have been able to establish rock

strength based on different electric logs which is comparable with the ARSL based on drilling data.

One exception is for harder zones which still some additional work remaining


ARSL: From other sources


Variation in properties: Anisotropy

Anisotropy effects Stress field Rock strength may have

anisotropic behavior Or large variations Effect when drilling: If directional change

determine an increase in mudweight this will increase drilling time and increase wear


Task 3 progress report

Task 3. Develop automatic well planning routine in DDS By developing algorithms that make more of the drilling

simulation automatically there is a possibility to increase the numbers of well scenario which is simulated

A new bit routine is underway. This routine will make it possible to automatically simulate different bits for each section and thereby increase the numbers of simulations performed and increase the value of planning


Summary

Up to now our project followed its original progress Task one, the software integration went well Drops believe that being part of a larger software

package to the oil companies will give economical results in near future

We believe that drilling simulation will be common in the future so the time works for us, not against us

We would like to thank NFR for giving a small company as ours the possibility to do research. Whiteout NFR support we would not have been able to do it


Example: Day to day follow up

3500

3600

3700

3800

3900

4000

4100

4200

4300

44000 5 10 15 20 25 30 35 40 45 50 55 60

Time (hrs)

Me

as

ure

d D

ep

th (

m)

8.5 in Pilot

8.5in Simulated

8.5in Actual

Trip for Bit Change

Bit Quits Drilling

RPM recommendations not followed

Rig was informed

that bit will wear out

before TD

Trying to save five

hours resulted in a

loss of 15+ hours

(or about $100.000) !

8 1/2” Section Time-Depth Curve

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