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Unformatted text preview: 1) it was 1.0 ppg higher than anticipated and (2) there was a possibility that the test results did not reflect a true test of the formation below the 9‐7/8 inch liner shoe. Although this fracture gradient test was questionable, BP chose not to retest the fracture gradient at the shoe and decided to drill ahead. After drilling the M57C sand interval, BP API 608174116901, March 26 APD (Revised Bypass) for the Macondo Well. 65 29 conducted a Geotap survey to determine the sand pore pressure. The sand pore pressure was determined to be 14.15 ppg. BP also converted this pore pressure to an estimated fracture gradient of 15.0 ppg. The open‐hole section drilled utilized a surface mud weight range of 14.1–14.5 ppg, which allowed for a safe drilling margin to be maintained between pore pressure and fracture gradient. Throughout this interval, however, BP encountered multiple problems associated with both lost returns and regressing pore pressures (1.9 ppg difference) between 17,001 and 18,066 feet. BP lost approximately 4,000 barrels (“bbls”) of mud in the production open‐hole interval. BP utilized loss circulation material in this interval to attempt to control these losses. Date
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