深水井环空圈闭压力管理方案研究

Study on Pressure Management of Annulus Pressure Buildup in Deepwater Wells

杨向前 张兴全 刘书杰 任美鹏

YANG Xiangqian ZHANG Xingquan LIU Shujie REN Meipeng

中海油研究总院有限责任公司, 北京 朝阳 100028

CNOOC Research Institute Co. Ltd., Chaoyang, Beijing 100028, China

除油套环空外，深水油气井套管环空圈闭压力无法释放，易造成套管挤毁等事故发生，需对环空圈闭压力进行管理，保障油气井生产安全。计算深水井在温度差下的环空圈闭压力，优化分析适用于深水的环空圈闭压力防治方法，结合管柱强度校核标准，建立深水井套管柱强度校核方法，最终形成环空圈闭压力管理设计方法。对于深水油气井，适用的圈闭压力防治方法为A环空压力释放、通过地层进行压力释放和套管外安装可压缩泡沫；考虑环空圈闭压力时，套管柱强度优选应同时采用平衡法和非平衡法进行套管强度校核；综合考虑防治方法和油套管强度校核结果，最终确定A环空圈闭压力控制范围，深水井环空圈闭压力管理方案研究对深水油气井安全高效开发提供技术支持。

The annulus pressure buildup (APB) in deepwater oil and gas wells may not be released even by employing a casing annulus resulting in accidents, such as casing collapse. Therefore, it is necessary to regulate the APB to ensure safety during oil and gas production. This study has calculated the trapped annular pressure in deepwater wells under different temperatures and analyzed and optimized the method to prevent and control the annular pressure in these wells. Using the strength standards for casing strings, this study has proposed a method to verify the strength of the casing string in the deepwater well and established a pressure management method for the trapped annulus. In terms of deepwater oil and gas wells, the control method for the trapped annular pressure involves relieving the pressure of the A-annulus through the formation pressure relief and wrapping the casing strings with compressed foam. The strength of the casing string must be verified using both equilibrium and nonequilibrium methods concerning the trapped annular pressure; the prevention and control methods must be considered together with these verification results to determine the pressure control range for the trapped A-annulus.

10.11885/j.issn.1674-5086.2018.04.10.01