四川超深海相气藏探井测试难点及对策

DIFFICULTIES AND COUNTERMEASURES IN TESTING ULTRA-DEEP-SEA FACIES EXPLORATION WELLS IN SICHUAN

四川地区超深层海相气藏茅口组-灯影组气藏埋深6600~8500 m,预测最高地层压力150 MPa,地层温度近180℃,且含有H2S,测试工况恶劣。APR测试工艺面临着测试工具尺寸选择受限、高温下橡胶件失效、钻井液稳定性差及沉淀卡埋管柱等系列挑战。在超深层海相气井测试实践基础上,通过管柱受力分析、优选耐高温橡胶密封件、提高结构强度、优化管柱组合等技术手段,有效解决了超深层海相气藏所带来的系列难题,形成了适用于超深层海相气藏探井的测试联作工艺,为超深海相气藏勘探评价提供了技术支撑。

The buried depth of Maokou formation-dengying formation of super deep Marine gas reservoir in Sichuan area is 6600~8500m.The maximum formation pressure is predicted to be 150MPa,the formation temperature is nearly 180℃,and it contains H2S.The test conditions are harsh and the process is complex.APR testing technology is faced with a series challenges such as limited size selection of testing tools,failure of rubber parts at high temperature,poor mud stability and precipitation stuck pipe string.Based on ultra deep Marine gas well testing practices,through such technical measures as string force analysis,optimizing high temperature resistant rubber seals,improving structure strength,optimizing tubing string combination,series of problems brought by the ultra deep Marine gas reservoir rhave been effectively solved.The combined testing techniques suitable for the exploration wells of ultra-deep Marine gas reservoir has been formed,which provides technical support for the exploration and evaluation of ultra-deep sea gas reservoir.