270 likes | 281 Views
Explore MEQ monitoring in liquid-dominated fields relying on injection for production maintenance. Test methods in a well-constrained scenario and transfer technology from The Geysers.
E N D
MEQ Monitoring of Injection at the Tiwi Geothermal Field, Philippines Ernest Majer1 and Gregg Nordquist2 1 Lawrence Berkeley National Laboratory 2 Unocal Geothermal EM-01G
Purpose 1. Investigate the utility of MEQ monitoring in heavily exploited liquid-dominated fields that will(are) rely(ing) on injection to maintain production. 2. Test applicability of MEQ methods in a well constrained case. a. Geochemical tracer tests b. Core hole c. 20 years of experience 3. Transfer technology developed at The Geysers. EM-01G
Objective Deploy multicomponent high resolution portable array to monitor MEQ activity and characteristics as a result of a controlled injection. a. Rate and distribution before and during injection. b. Relate seismic attributes to reservoir properties and transport. c. Provide a design for optimal long term MEQ monitoring and analysis. EM-01G
Funding/Cooperation Heavily subsidized by Unocal with instrumentation support from IRIS. Project initiated by Unocal. a. Unocal: $50K in direct salary support to Unocal employees, shipping, and field support. Also paid expenses and travel of IRIS technician to install array. b. IRIS provided thirteen (13) instruments for six (6) months. c. LBNL will process and interpret data . Provide recommendations of future approach. d. Unocal will provide injection data, geology, and joint interpretation of results. EM-01G
Plan and Approach 1. Augment current array with a high resolution digital multicomponent station. a. Current array analog with 40 to 50 Hz bandwidth (8 stations) since 1987 ( 200 to 300 m) b. Deploy 24 bit 200 samples/sec. network of 12 stations centered on injection zone with 3 component 4.5 Hz geophone with continuous recording over entire period. 2. Apply a variety of processing and interpretation techniques a. Precision location using correlation analysis. b. Joint inversion for velocity and location in 3-D. c. Examine spatial and temporal distribution of events in relation to injection schedules. d. Examine MEQ attributes i. Size ii. Mechanism of events 3. Deployment of instruments in late February of 2001. a. Injection period from March 7 to June 30, 2001 b. Use large array to focus studies of detailed array. c. Over 275 G bytes of data recorded. EM-01G
Injection Data EM-01G
EM-01G 1994
EM-01G 1998/99
Plans for Project completion Data conditioning (July and August) a. Time align and sort data into proper sequence b. Hand scan all data for events c. Pick events for analysis Data processing and interpretation ( Sept-Oct) a. 3-d velocity model and location b. Correlation analysis with possible events c. Correlate with injection data (tracer) and geology d. Provide recommendation for future deployment e. Final report EM-01G
Summary Highly focused project with specific objectives Unique data set with application to a variety of cases True partnership between industry and government Results in public domain MEQ work will be continued as part of DOE-LBNL/CEC project at The Geysers EM-01G
Acknowledgements Al Protacio - Unocal field support UC/LBNL Data Processing John Peterson, Bob Urhammer, Tiffany Foo IRIS - Field Equipment DOE and Unocal - Financial Support EM-01G