川渝地区龙马溪组页岩储层水化特征评价方法

A New Method for Evaluating the Characteristics of Hydration in the Longmaxi Shale Gas Reservoir in Sichuan-Chongqing Area

高书阳 豆宁辉 林永学 柴龙 刘锐

GAO Shuyang DOU Ninghui LIN Yongxue CHAI Long LIU Rui

页岩油气富集机理与有效开发国家重点实验室, 北京 100101; 中国石化石油工程技术研究院, 北京 100101; 中石化胜利石油工程有限公司钻井工程技术公司, 山东东营 257061

State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Developemt, Beijing, 100101, China; Sinopec Research Institute of Petroleum Engineering, Beijing, 100101, China; Drilling Engineering & Technology Company, Sinopec Shengli Oilfield Service Corporation, Dongying, Shandong, 257061, China

为有效评价页岩地层水化特征变化规律，引入了新评价方法，并对川渝地区龙马溪组页岩的储层水化特征进行了评价。分析了川渝地区龙马溪组页岩的岩石组构和理化特征，证明滚动回收、线性膨胀等常规试验方法不能有效评价不同钻井液条件下龙马溪组页岩的井眼稳定性能；分别介绍了基于岩石强度刻划技术的页岩力学性能评价方法、基于CT层析成像技术的裂缝扩展评价方法和基于压力穿透技术的微裂缝封堵评价方法，并用取自川渝地区龙马溪组的页岩岩心进行了评价试验。试验发现，岩石连续刻划技术可定量评价页岩微观组构对水化后页岩强度的影响程度，CT层析成像技术可用于直观描述水化后页岩内部微观结构的变化，压力穿透试验可有效评价压力在页岩中的穿透效应，并可指导页岩封堵材料粒径的选择。研究表明，上述3种方法可有效评价川渝地区龙马溪组页岩水化后性能的变化，可作为该地层井眼稳定性评价的常用方法。

A new method has been introduced in order to effectively evaluate the changes in hydration characteristics of shale formations.It is also used to evaluate the reservoir hydration characteristics of Longmaxi shale in Sichuan and Chongqing area.This paper analyzes the rock fabric and physiochemical features of Longmaxi shale,showing that the conventional test methods like rolling recovery and linear expansion cannot effectively evaluate the wellbore stability in Longmaxi shale under different drilling fluid conditions.Also,this paper explains the method for evaluating rock mechanical properties based on rock depiction technique,the method for evaluating the fracture extension based on CT imaging technique and the method for evaluating the micro-fracture sealing based on pressure penetration technique,and tests were made on the cores taken from Longmaxi shale in Sichuan and Chongqing area.The tests showed that the continuous rock depiction technique could quantitatively evaluate the effect of micro shale fabric on the strength of hydrated shale.CT imaging technique could also be used to visually describe the changes in the internal micro-structure of shale.Finally,the pressure penetration method could effectively evaluate the penetration effect of shale in shale and could help select the size of shale plugging grains.The study showed that the above three methods could effectively evaluate the changes of Longmaxi shale properties after hydration and could be used as a common method for evaluating the wellbore stability in this area.

国家自然科学"页岩油气高效开发基础理论研究"（编号：51490650）和国家科技重大专项"彭水地区常压页岩气勘探开发示范工程"（编号：2016ZX05061）联合资助。

https://doi.org/10.11911/syztjs.2018089