适用于大注采气量水平井注采能力测试的连续油管测试技术——以重庆相国寺地下储气库为例

Coiled tubing testing technology for testing the injection–production capacity of horizontal wells with high gas injection–production rates: A case study of the Xiangguosi Underground Gas Storage in Chongqing

重庆相国寺地下储气库的注采井以大斜度井和水平井为主,完井管柱复杂且单井注采气量大,常规的测试工具、仪器和工艺都无法满足气井注采能力测试的需要,亟需研发与之相适应的测试技术。为此,通过工具配套、仪器改进、工艺优化,形成了适用于该储气库大注采气量水平井注采能力测试的连续油管测试技术,在现场成功进行了10口井12井次的注采能力测试,并对测试结果进行了对比分析。研究结果表明:①所形成的技术能够满足大注采气量水平井注采能力测试的要求,测试获得的气井最大注气量为260×10~4 m^3/d,最大采气量为225×10~4 m^3/d;②同一口井的注采能力存在着差异,因而有必要针对每口井在不同注采周期进行注采能力的测试与评价;③大注气量情况下,近井地带呈现高速非达西渗流状态,对注采安全有可能形成威胁,周期注气后近井地带储层温度降低将影响库容大小。结论认为,所形成的连续油管测试技术录取的数据真实可靠,为储气库注采井的注采能力评价、单井注采计划安排和库容盘点等提供了技术支撑。

The injection-production wells of the Xiangguosi Underground Gas Storage(UGS)in Chongqing are mostly highly-deviated wells and horizontal wells.The completion strings are complex and the gas injection-production rate of single well is high,so it is difficult to test the injection-production capacity of gas wells by using conventional testing tools,instruments and processes.For this reason,it is in urgent need to develop a suitable testing technology.In this paper,a coiled tubing testing technology suitable for the injection-production capacity testing of horizontal wells with high gas injection-production rate in the Xiangguosi UGS was developed through tool matching,instrument improvement and process optimization.And this technology has been successfully applied to the injection-production capacity testing of 10 wells by 12 times.Finally,the testing results were comparatively analyzed.And the following research results were obtained.First,this coiled tubing testing technology can satisfy the requirements of injection-production capacity testing of horizontal wells with high gas injection-production rates.And the tested maximum gas injection and production rates are 260×10^4 m^3/d and 225×10^4 m^3/d,respectively.Second,even in the same well,the injection-production capacity is different,so it is necessary to test and evaluate the injection-production capacity of each well in different injection and production cycles.Third,at high gas injection rate,high-speed non-Darcy percolation occurs near the wellbore and it may threaten the injection-production safety.And after periodic gas injection,the decline of reservoir temperature near the wellbore will influence the storage capacity.In conclusion,this coiled tubing testing technology presents real and reliable data,and it provides a technical support for the injection-production capacity evaluation of injection-production wells of underground gas storages,the arrangement of single-well injection-p roduction plan and the check of storage capacity.