深水浅层气钻井风险评估与控制技术

Risk assessment and control technology for deep water and shallow gas drilling

喻贵民 顾纯巍 宋宇 赵宇航 李磊 刘和兴 杜威 赵少伟

YU Guimin GU Chunwei SONG Yu ZHAO Yuhang LI Lei LIU Hexing DU Wei ZHAO Shaowei

中海石油(中国)有限公司 中国石油大学(北京) 中海石油(中国)有限公司湛江分公司

CNOOC (China) Co., Ltd., Beijing 100033, China China University of Petroleum (Beijing), Beijing 102249, China Zhanjiang Branch of CNOOC (China) Co., Ltd., Zhanjiang 524000, Guangdong, China

在深水油气田开采过程中常钻遇浅层气，浅层气是聚集在海底的超压气体，由于预测难、控制手段少，通常采用更换井位的方式对存在浅层气的区域进行规避，严重制约了钻井井口选址范围，甚至无法实现油藏勘探目的。基于ANSYS Fluent软件，采用VOF模型和k-ε湍流模型，建立了浅层气放喷多相流体瞬态流动计算模型，得到了不同压力系数、储藏规模和井眼尺寸条件下的浅层气喷流特征，建立了基于气藏压力、储藏规模的浅层气放喷数值模型，提出了对处于中高风险等级的浅层气采取主动放喷技术的防治方法。该研究对主动应对浅层气地质灾害具有理论指导意义。

Shallow gas is often encountered during the development of deep-water oil and gas fields. Shallow gas is an overpressure gas accumulated on the seabed. Due to the prediction difficulty and few control methods, the area where shallow gas exists is usually avoided by changing well positions. This restricts the site selection of drilling wellheads, and even fails to achieve the purpose of reservoir exploration. Based on ANSYS Fluent software, by using VOF model and - turbulence model, a calculation model for transient multiphase fluid flow when shallow gas blowout was established, and the shallow gas blowout features under the conditions of different pressure coefficients, reservoir scales, and wellbore sizes were obtained. Based on the gas flow characteristics and the reservoir scale, a numerical model of shallow gas blowout was established, and a prevention and control method of adopting active blowout technology for shallow gas at medium and high-risk level was put forward. This research has theoretical guiding significance for actively responding to potential geological disasters caused by shallow gas.

10.13639/j.odpt.2022.03.005