致密砂岩气藏气体钻井高效建产的机理分析及展望

Mechanism Analysis and Prospect of Efficient Production of Gas Drilling in Tight Sandstone Gas Reservoirs

李皋 张毅 李红涛 孟英峰 杨旭

LIGao ZHANGYi LIHongtao MENGYingfeng YANGXu

油气藏地质及开发工程全国重点实验室·西南石油大学, 四川 成都 610500 油气钻完井技术国家工程研究中心欠平衡/气体钻井实验室, 四川 成都 610500

State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, Southwest Petroleum University, Chengdu, Sichuan 610500, China Underbalanced/Gas Drilling Laboratory, National Engineering Research Center of Oil & Gas Drilling and Completion Technology, Chengdu, Sichuan 610500, China

气体钻井开发致密砂岩气藏具有避免储层损害的天然优势，然其机理尚不够清晰；致使高效建产存在偶然性。为此，系统性回顾了气体钻井开发致密砂岩气藏的经验与教训，以迪北、川西地区气体钻井开发致密气藏实践为例，基于甲烷浓度、出口湿度等随钻监测数据，结合岩屑X射线衍射、测井资料分析高效建产机理。研究发现，高产井产气点井深与砂泥岩岩性界面高度对应，证实了其衍生的缝网系统为主要储气空间和产气通道，是井轨迹的重点穿越目标，未来应加强提高气体钻进安全穿越砂泥岩夹层的能力。受断裂带影响，有水气藏中下部地层水会运移至断层下降盘的上部，因此应以构造高点、断层上升盘为井位部署依据，并结合成藏演化与构造运动历史进行优化。后续还需深入工程地质力学研究，关注岩性界面缝的有效性和有水气藏中气水关系及其影响，同时发展复杂环境下的气体钻完井工艺及工具。

Gas drilling for the development of tight sandstone gas reservoirs is of natural advantages in avoiding reservoir damage. However, the lack of clear understanding of its mechanisms introduces uncertainties regarding its ability to achieve efficient production. To address this issue, a systematic review was conducted on the experiences and lessons learned from gas drilling for the development of tight sandstone gas reservoirs. The gas drilling practices in the Dibei and western Sichuan regions were used as examples. Based on drilling monitoring data such as methane concentration and outlet humidity, and through the analysis of cuttings' X-ray diffraction and logging data, the mechanisms for efficient production were examined. The study revealed that productive gas points in high-yield wells corresponded to the height of the sandstone-shale lithological interface, confirming that the derived fracture network system serves as the primary gas storage space and gas production pathway, making it a crucial target for wellbore trajectory. Influenced by fault zones, water from the lower part of aquifers could migrate to the upper part of the fault drop zone. Therefore, well deployment should be based on high structural points and fault uplift zones, taking into account reservoir evolution and tectonic movement history for optimization. It is believed that further in-depth research in engineering geological mechanics is needed, focusing on the effectiveness of lithological interface fractures, the relationship between gas and water in aquifers, and their impacts. Additionally, the development of gas drilling and completion techniques and tools for complex environments should be pursued.

10.11885/j.issn.1674-5086.2023.06.17.01