长庆油田区块井眼尺寸效应与井壁稳定性分析  

Analysis of wellbore size effect and wellbore stability in Changqing oilfield block

作　　者：王萍[1,2] 樊佳勇[1,2] 韩成福 王亮 屈展[1,2] 黄海[1,2] 顾甜利[1,2] 许愿 WANG Ping;FAN Jiayong;HAN Chengfu;WANG Liang;QU Zhan;HUANG Hai;GU Tianli;XU Yuan(College of Petroleum Engineering,Xi’an Shiyou University,Xi’an 710065,China;Shaanxi Provincial Key Laboratory of Oil and Gas Well and Reservoir Seepage and Rock Mechanics(Xi’an Shiyou University),Xi’an 710065,China;Changqing Drilling Branch of CNPC Chuanqing Drilling Engineering Co.,Ltd.,Xi’an 710018,China;Student Office of Xi’an Shiyou University,Xi’an 710065,China)

机构地区：[1]西安石油大学石油工程学院,西安710065 [2]陕西省油气井及储层渗流与岩石力学重点实验室(西安石油大学),西安710065 [3]中国石油集团川庆钻探工程有限公司长庆钻井分公司,西安710018 [4]西安石油大学学生处,西安710065

出　　处：《中国科技论文》2023年第1期91-96,共6页China Sciencepaper

基　　金：国家自然科学基金资助项目(51974255,51874240);陕西省自然科学基础研究计划项目(2020JM-544);中国石油集团川庆钻探工程有限公司长庆钻井总公司技术开放项目(290021128)。

摘　　要：为了研究长庆油田区块井眼尺寸与井壁稳定性的关系,对不同开孔直径的岩样进行单轴抗压强度试验,得到开孔直径与抗压强度的关系,并以此建立考虑井眼尺寸效应的井壁坍塌压力、破裂压力的数学模型,计算得到钻井液坍塌压力当量密度与破裂压力当量密度。结果表明:井眼尺寸减小,抗压强度随之增加,对应的坍塌压力减小且破裂压力增加,钻井液安全密度窗口范围随之扩大,井眼尺寸减小有利于井壁稳定。研究对小井眼现场安全钻井有一定的指导意义。In order to study the relationship between wellbore size and wellbore stability in Changqing oilfield block, uniaxial compressive strength experiments were carried out on rock samples with different pore sizes, and the relationship between pore sizes and compressive strengths of rocks was obtained. The mathematical models of wellbore collapse pressure and fracture pressure considering the effect of wellbore size were established, and the equivalent density of the collapse pressure and the equivalent density of the fracture pressure were calculated. The experimental analysis shows that the compressive strength increases with the decrease of the wellbore size, with the decrease of corresponding collapse pressure and increase of the fracture pressure, and the safe density window range of the drilling fluid expands accordingly. The study has certain guiding significance for safe drilling on small boreholes.

关 键 词：单轴抗压强度 尺寸效应 坍塌压力 破裂压力 井壁稳定 

分 类 号：TE246[石油与天然气工程—油气井工程]