Needs and requirements for high temperature instrumentation in

extreme geothermal environment

-description based on EC HITI application and recent

developments

Dr. Ragnar K. Ásmundsson, ÍSOR

Presentation for ENGINE Launching Conferance, Feb. 2006

Members of HITI

1 ÍSOR Iceland2 CNRS Montpellier France3 BRGM France4 Calidus Engineering Ltd. U.K5 ALT Luxembourg6 ANTARES Germany7 Oxford Applied Technology U.K.8 GFZ-Potsdam Germany9 CRES Greece

HIgh Temperature Instruments for supercritical geothermal reservoir characterization and exploitation

Submitted in Dec. 2004

IDDP – Iceland Deep Drilling Project

The main objective of the HITI project is to develop sensors and methods to accurately determine the existing conditions of the reservoir and fluids in-situ at the base of a deep geothermal system in Reykjanes, Iceland.

Figure 1. Pressure-enthalpy diagram for pure H2O with selected isotherms. The conditions under which steam and water coexist is shown by the shaded area, bounded by the boiling point curve to the left and the dew point curve to the right. The arrows show various different possible cooling paths (Fournier, 1999).

Main objectives

Developing downhole instruments capable of tolerating temperatures over 300 °C, and preferably up to 500 °C.

• develop and field test downhole instruments and methods tolerating temperatures above current limits. These instruments include: temperature, pressure, fluid and rock electrical resistivity, natural gamma radiation, televiewer acoustic images, pH, casing collar locator, casing monitoring, fluid sampling, fluid flow, chemical temperature sensing and organic tracers,

• adapt an existing HPHT (High Pressure, High Temperature) laboratory facility to the measurement of electrical resistivity at appropriate reservoir conditions and varying fluid nature,

• validate the new instruments from the analysis of downhole data and samples (either core or fluid) from field tests in either hot existing wells, or the new IDDP hole.

Tool/method deliverables

1 MultiSensor, PLT400, 400°C2 High temperature wireline T sensor3 Fluid sampler, 400°C4 Gamma ray (GR) detector, 300 °C5 Dual Laterolog (DLL), 300 °C6 Televiewer with casing thickness evaluation to 300°C7 Distributed temperature sensing8 HPHT rig 600°C laboratory9 Na-Li temperature evaluation to 500°C10 Organic tracers to 350°C

400°C Memory tools, temperature, pressure, flow, casing collar and

conductivity

Comparison: Kuster K10, 350°C (4h)

HITI: To develop a memory based production-logging tool (Multi-sensor) with additional wireline surface readout transmission sub, capable of measuring pressure (P), temperature (T), flow rate (Q), casing collar location (CCL) and fluid conductivity (Cw) rated for use at temperatures of 400°C (CalEng)

350 °C Pressure / Temperature / flow

320 °C wireline temperature sensor

200 °C Pressure (qtz) / Temperature / Flow / Gamma - production tool – 200 °C rated digital electronics, 140MPa (20kpsi).Higher temperatures and functionality under development

HITI: To develop a wireline sensor measuring temperatures up to 320°C (BRGM)

Comparison: Kuster, 177°C, 114 MPa

DEVELOPED

Fluid sampler, 400 °C

250 / 350 / 400 °C Fluid sampler - sold into Japan

HITI: To develop a memory based borehole fluid sampler system to capture high quality fluid samples at well temperatures of 400 °C and transfer these to surface transportation vessels for onward shipment and analysis (CalEng).

Gamma ray (GR) detector, 300 °C

HITI: To develop a natural gamma radioactivity wireline logging sensor with 300 °C rating for basement alteration identification at reservoir level (ANTARES)

200 °C Temperature / Gamma / CCL - sold into Europe and USA 

Dual Laterolog (DLL), 300 °C

HITI: To develop a dual laterolog wireline logging sensor with 300 °C rating for rock electrical resistivity measurements and reservoir porosity evaluation

350 °C Resistivity tool - dual laterolog, 100MPa, microprocessor- digital electronics

DEVELOPED

DEVELOPED

Televiewer with casing thickness evaluation to 300°C

HITI: Casing monitoring tool prototype improved from deployment at the test sites (ALT)

Distributed temperature sensing, 300°C

HITI: DTS sensor cable will be tested in a high-enthalpy geothermal reservoir in Iceland and further developed (GFZ)

Typical borosilicate glass can withstand temperatures up to 900°F (482°C) before deterioration begins. In the photo above, the glow of the furnace can be seen in the core bar as a glass combination begins the transformation process.

Groß Schönebeck°: 143°C, 4.2 km

HPHT rig 600°C laboratory

HITI: To modify the Montpellier University Paterson press in order to allow for electrical resistivity measurements at temperatures up to 600 °C, pressures up to 200 MPa, and variable fluid salinity (D8 deliverable as an "HPHT" rig).

Complex resistivity measurements on mantle rocks were achieved with success up to 800°C (Gilbert & Mainprice)

HITI: To estimate the reservoir temperature from chemical analyses performed on fluid samples collected either in-situ or at surface. Isotopic Li analyses, performed by ICP-MS/MC on high temperature fluid samples for the first time, are proposed to ameliorate the knowledge of this geothermometer and to confirm the nature of the reservoir rocks in contact with the geothermal fluid. To use organic compounds (sulfonate naphthalene family) to carry out tracer tests in high temperature geothermal wells (up to 350°C) in order to detect possible hydraulic connections between wells and to estimate the reservoir capacity (storativity) and the fluid flow rate.

Organic tracers to 350°C and Li analysis

Complete oxide isolation of all transistors

TiW barrier layer on all metals and contacts

Variable width oxide trench

Twin well technology

CrSi thin film resistors available N+poly to N+silicon linear capacitor

0.8 micron 5 volt digital capability

Designed for 50,000 hours of 225°C operation

Final test at 225°C ambient

Burn-in at 250°C

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