川西北部地区栖霞组超深高温气井酸压技术

An acid fracturing technology suitable for high-temperature ultradeep gas wells in the Qixia Formation in the north of Western Sichuan

曾冀 马辉运 刘俊辰 苟波 李金穗 杨林

ZENG Ji MA Huiyun LIU Junchen GOU Bo LI Jinsui YANG Lin

中国石油西南油气田分公司工程技术研究院 四川页岩气勘探开发有限责任公司 西南石油大学油气藏地质及开发工程国家重点实验室 中国石油西南油气田分公司致密油气勘探开发项目部

Engineering Technology Research Institute, PetroChina Southwest Oil and Gas Field Company, Chengdu 610017, China Sichuan Shale Gas Exploration and Development Company, Chengdu 610051, Sichuan, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China Tight Oil and Gas Exploration & Development Project Department, PetroChina Southwest Oil and Gas Field Company, Chengdu 610056, Sichuan, China

川西北部地区栖霞组埋藏深、温度高、不同程度发育小洞和中洞，酸压改造面临摩阻高、酸岩反应速率快和酸蚀裂缝导流能力保持困难等难题。为提高栖霞组储层酸压设计的针对性，建立了酸岩反应热模型，开展了多场耦合酸压裂缝形态模拟。模拟结果表明：酸岩反应热会提高酸岩反应速率，降低酸蚀缝长，200 m³酸量对酸蚀缝长的影响最高达9 m；施工排量恒定时，酸蚀缝长随着酸量的增加而增加，但增加幅度逐渐减小。开展了4井次现场试验，井均测试产气量67.03×10⁴ m³/d。现场试验表明，酸岩反应热对超深高温气井酸蚀裂缝形态的影响不可忽略，多场耦合酸压设计方法在川西北部地区栖霞组具有较好的适应性。

The Qixia Formation in the north of Western Sichuan is characterized by great burial depth, high temperature and small and medium pores with different development degrees, and its acid fracturing is faced with a series of difficulties, e.g. high friction resistance, fast acid-rock reaction and difficult maintenance of flow conductivity of etched fractures. In order to improve the pertinence of acid fracturing design to the reservoir of Qixia Formation, the acid-rock reaction heat model was established and the morphologies of the fractures induced by multi-field coupling acid fracturing were simulated. It is indicated that the acid-rock reaction heat can increase the acid-rock reaction rate and reduce the length of etched fracture. When there is 200 m acid, the maximum effect on the length of etched fracture is 9 m. When the construction displacement is constant, the length of etched fracture increases with the increase of acid volume, but its increasing amplitude declines gradually. Field tests were carried out 4 well times and the average gas production per well was 67.03×10 m/d. It is revealed that the effect of acid-rock reaction heat on the morphologies of etched fractures in high-temperature ultradeep gas wells shall not be neglected and multi-field coupling acid fracturing design method is better adaptable to the Qixia Formation in the north of western Sichuan Basin.

10.13639/j.odpt.2019.03.016