基于页岩油井置换条件下的环空压力分布  

Annular pressure distribution under the displacement conditions of shale oil wells

作　　者：邓嵩[1] 殷文 崔猛 赵飞 王江帅 李朝玮 闫霄鹏 DENG Song;YIN Wen;CUI Meng;ZHAO Fei;WANG Jiangshuai;LI Chaowei;YAN Xiaopeng(School of Petroleum and Natural Gas Engineering,Changzhou University,Changzhou 213164,China;CNPC Engineering Technology Research and Development Co.,Ltd.,Beijing 102206,China)

机构地区：[1]常州大学石油与天然气工程学院,江苏常州213164 [2]中国石油集团工程技术研究院有限公司,北京102206

出　　处：《常州大学学报（自然科学版）》2024年第2期1-9,共9页Journal of Changzhou University：Natural Science Edition

基　　金：中国石油常州大学创新联合体资助项目(2021DQ06);江苏省高等学校基础科学(自然科学)研究面上项目(22KJD430001)。

摘　　要：在置换过程中,井筒内的钻井液与井周地层流体形成了动态的流体交换现象,导致环空中流体组成发生变化,进而引起环空压力的变化。现有环空压力计算模型无法准确预测基于置换条件下的压力分布,因此建立了一种基于置换条件下页岩油井环空压力计算新模型。通过数值模拟方法分析了影响环空压力分布的各因素,结果表明:①保持环空流入地层的排量不变,增加地层流入环空的排量,环空压力降低约为1.19 MPa/L;②环空压力分布曲线上会出现一个拐点,且拐点位置与置换点位置一致;③随着置换流体页岩油密度的增大,环空压力升高约为0.034 MPa/(kg·m^(-3))。研究结果可为发生在复杂地层钻井中的置换、漏失和溢流等问题提供一定的理论参考。During the displacement process,dynamic fluid exchange occurs between the fluid in the wellbore and the surrounding formation fluid,leading to changes in the composition of the annular fluid and subsequently causing variations in annular pressure.Existing models for calculating annular pressure cannot accurately predict pressure distribution based on displacement conditions.Therefore,this study establishes a novel model for calculating annular pressure in shale oil wells under displacement conditions.Through numerical simulation analysis of various influencing factors on annular pressure distribution,the results indicate:①Maintaining a constant flow rate of annular fluid entering the formation,increasing the flow rate of formation fluid entering the annulus results in a reduction of annular pressure by approximately 1.19 MPa/L;②An inflection point will appear on the annular pressure distribution curve,and the inflection point position is consistent with the displacement point position;③With the increase of shale oil density of formation fluid,the annular pressure increases by approximately 0.034 MPa/(kg·m^(-3)).The results of this study can provide some theoretical reference for problems such as displacement,leakage and overflow in drilling in complex formations.

关 键 词：油基泥浆 置换现象 环空压力 页岩油 

分 类 号：TE21[石油与天然气工程—油气井工程]