各向异性地层中随钻地层测试压力响应数值模拟  

Numerical simulation on pressure response of formation testing whiledrilling in anisotropic formations

作　　者：马天寿[1] 曹刚 彭念 田薇 王强 MA Tianshou;CAO Gang;PENG Nian;TIAN Wei;WANG Qiang(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University),Chengdu 610500,Sichuan;No.10 Oil Production Plant,Changqing Oilfiled Company,PetroChina,Xi’an 710021,Shannxi;Sichuan Aerospace Fenghuo Servo Control Technology Co.,Ltd.,Chengdu 611130,Sichuan)

机构地区：[1]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 [2]中国石油长庆油田分公司第十采油厂,陕西西安710021 [3]四川航天烽火伺服控制技术有限公司,四川成都611130

出　　处：《长江大学学报（自然科学版）》2024年第1期66-78,F0003,共14页Journal of Yangtze University(Natural Science Edition)

基　　金：国家自然科学基金项目“地层压力随钻测试压力响应的数值模拟与物模实验”(41874216);教育部霍英东基金项目“钻井扰动影响下地层压力随钻测试响应机理及数值模拟方法”(171097)。

摘　　要：在随钻地层测试器测试过程中,钻井液动态侵入和地层各向异性会导致不同的压力响应特征,并直接影响地层压力测试结果的解释精度。为此,基于各向异性多孔介质渗流理论,建立了钻井液侵入条件下横观各向同性地层随钻地层测试压力响应数学模型,采用有限元方法对模型进行求解,通过与经典解析解对比进行了模型验证,并分析了渗透率各向异性、地层产状、抽吸间歇时间、抽吸探头半径对随钻地层测试压力响应的影响规律。结果表明:在抽吸前阶段,地层各向异性和地层产状对钻井液侵入导致的井周增压影响较大;在压力恢复阶段,由于井周地层增压作用的影响,测试压力响应初始值会高于原始地层压力,且压力呈先升高后降低的演化趋势;渗透率各向异性程度越小、地层倾角和倾向越小,抽吸压降阶段的压力响应初始值越大、压降值越大、压力恢复速率越低;抽吸间隔时间和抽吸探头半径对压力响应也有一定影响,抽吸间隔时间越小,测试初始压力越大,探头半径越大,压力恢复速率越快。揭示了渗透率各向异性对随钻地层测试压力响应的影响规律,研究结果可为随钻地层测试结果解释和地层参数反演提供理论依据。Dynamic intrusion of drilling fluid and formation anisotropy will lead to different pressure response characteristics during formation testing and directly affect the interpretation accuracy of formation pressure test results.Therefore,based on the seepage theory of anisotropic porous media,a mathematical model of pressure response of formation testing while drilling in transverse isotropic formation under drilling fluid intrusion was established.The finite element method was used to solve the model,and the model was verified by comparing with the classical analytical solution.The influence of permeability anisotropy,formation occurrence,suction interval time and suction probe radius on formation pressure response while drilling is analyzed.The results show that the degree of formation anisotropy and formation occurrence have great influence on the pressure increase around the well caused by drilling fluid invasion in the pre-pumping stage.After formation pressurization around the well,the initial response value of formation pressure tested while drilling is higher than the original formation pressure.During pressure recovery,the pressure first increases and then decreases.The smaller the anisotropy of permeability,formation dip and inclination are,the larger the initial pressure response value and the pressure drop value are in the suction pressure drop stage,and the slower the pressure recovery rate is in the pressure recovery stage.The suction interval time and the suction probe radius also affect the pressure response behavior.The smaller the suction interval time is,the larger the initial pressure is.The larger the probe radius,the faster the pressure recovery rate.This paper reveals the influence of permeability anisotropy on the pressure response of formation testing while drilling,which can provide theoretical basis for interpretation of formation testing results and inversion of formation parameters.

关 键 词：随钻地层测试 钻井液侵入 各向异性 渗透率 压力响应 数值模拟 

分 类 号：TE21[石油与天然气工程—油气井工程]