The objective of this field test is to validate several technologies for non-invasive well integrity assessment using existing wells with a known completion. The tests were made at the Cymric oil field, which is a steam flood operation. The wells therefore undergo similar downhole conditions as geothermal wells. The Cymric field is mainly a cyclic steam operation where wells are 1000-15-00 ft in depth and the reservoir occupies the bottom 400ft. The maximum temperatures can exceed 500 degrees F and the well spacing is very close, often less than 50m. The field plan consisted of applying the Time Domain Reflectometry (TDR) method to the wells. The input voltages were set as 70 V shows the TDR responses at frequencies of 450 kHz, 2500 kHz, and 4500 kHz. There is a summary report will full information about the field tests. TDR response of 450 kHz were made on the final morning in well TO15-5, using TO15-6 as a return electrode. The input voltage was set as 70V. We can set a TDR return at 1.8 – 2 µs, which is the reflection at about 738—862 ft deep. The shape of the TDR return indicates this is an open termination. Based on our knowledge of the well structure, this return is from the end of the production string.
Tuesday, October 1, 2019 12:35 pm