钻井液对裂缝性地层气侵的影响模拟研究

详细信息    查看全文 | 推荐本文 |

英文篇名：Simulation Study on the Effects of Drilling Fluid on Gas Cut from Fractured Formations 作者：方俊伟 ; 朱立鑫 ; 罗发强 ; 张俊 ; 王永 ; 黄维安 ; 牛晓 英文作者：FANG Junwei;ZHU Lixin;LUO Faqiang;ZHANG Jun;WANG Yong;HUANG Weian;NIU Xiao;Research Institute of Petroleum Engineering Northwest Oil Company of SINOPEC;School of Petroleum Engineering, China University of Petroleum (Huadong);Research Institute of Petroleum Engineering,Northwest Oil Company of SINOPEC; 关键词：裂缝性地层 ; 重力置换气侵 ; 钻井液性能 ; 模拟 ; 动压 英文关键词：Fractured formation;;Gas cut caused by gravity displacement;;Performance of drilling fluid;;Simulation;;Dynamic pressure 中文刊名：ZJYW 英文刊名：Drilling Fluid & Completion Fluid 机构：中国石化西北油田分公司石油工程技术研究院;中国石油大学(华东)石油工程学院; 出版日期：2019-05-30 出版单位：钻井液与完井液 年：2019 期：v.36;No.199 基金：山东省重点研发计划“基于主客体聚合物的超临界二氧化碳流体增黏剂的研制及其机理”(2018GSF116008);; 国家科技重大专项十三五课题“致密油气开发环境保护技术集成及关键装备”(2016ZX05040-005);国家科技重大专项“塔里木盆地碳酸盐岩油气田提高采收率关键技术示范工程”(2016ZX05053-014) 语种：中文; 页：ZJYW201903004 页数：6 CN：03 ISSN：13-1118/TE 分类号：28-33

摘要

裂缝性地层钻进过程中,容易发生重力置换气侵,裂缝内气体进入井筒后,控制不当易引发井涌、井漏、井喷等复杂情况,气侵发生时裂缝附近的压力波动容易导致井壁失稳。在塔中北坡顺南区块裂缝特征参数分析基础上,使用Gambit建模软件进行前期建模和网格划分,建立了井筒与裂缝的三维模型;运用ANSYS Fluent流体力学软件,建立多相流模型,分析置换过程中裂缝开口处动压对裂缝开口处井壁稳定性的影响;以现场某井的数据为参考,模拟分析钻井液的密度、黏度、排量对重力置换气侵的影响。结果表明,置换气侵发生时,由于压差较大,瞬间流速较大,在0.1 s内降低至较低水平;动压的最大值在裂缝的上下两端,最小值在裂缝中上部,这3个位置的裂缝口缝宽容易增加,引起井壁失稳;钻井液的密度、黏度变化对气侵时裂缝口的动压影响较小,变化量小于6%,对气侵速度的稳定值影响也较小;而排量对于气侵时裂缝口的动压影响较大,变化量达到66.9%,降低钻井液排量有利于井壁稳定。
        Gas cut caused by gravity displacement is frequently encountered when drilling fractured formations. Well kick, mud loss and well blowout will happen if gas entering the wellbore from fractured formations is not correctly handled. When gas kick is happening,pressure fluctuation around the fractures will result in borehole wall instability. In laboratory studies, based on the analyses of the characteristic parameters of the fractures in Block Shunnan located in the north slope of Tazhong, the early stage modeling and meshing were done using the modelling software Gambit, and 3D models for wellbore and fractures were established. Using ANSYS Fluent hydromechanical software, a multiphase flow model was established with which the effects of the dynamic pressure at the mouth of a fracture on the stability of the borehole wall at the same place during gravity displacement were analyzed. Drilling data of a well, such as the density, viscosity and flow rate of the drilling fluid were used to analyze their effects on gas cut caused by gravity displacement.It was found that when gravity displacement took place, high pressure differential resulted in high instant flow rate of gas, which was then reduced to a low level in just 0.1 sec. The maximum dynamic pressure was found at the upper and lower ends of the fracture, while the minimum dynamic pressure was found at the middle-upper position of the fracture. The widths of the fracture at these three points were easy to increase, causing the wellbore to destabilize. Changes in the density and viscosity of the drilling fluid caused change in the dynamic pressure at the mouth of the fracture by only 6%. The steady rate of gas cut was also less affected by the changes in the density and viscosity of the drilling fluid. On the other hand, flow rate of the drilling fluid during gas cut greatly affected the dynamic pressure at the mouth of the fracture, causing the dynamic pressure to change by 66.9%, indicating that reduced flow rate of drilling fluid during gas cut is beneficial to bringing gas cut under control.

引文

[1]林安村,韩烈祥.罗家16井井喷失控解读--过平衡钻井中的井控问题[J].钻采工艺,2006,29(2):20-22.LIN Ancun,HAN Liexiang.Analysis of blowout out of control in well Loujia 16[J].Drilling&Production Technology,2006,29(2):20-22.
    [2]韩子轩,林永学,柴龙,等.裂缝性气藏封缝堵气技术研究[J].钻井液与完井液,2017,34(1):16-22.HAN Zixuan,LIN Yongxue,CHAI Long,et al.Plugging micro-fractures to prevent gas-cut in fractured gas reservoir drilling[J].Drilling Fluid&Completion Fluid,2017,34(1):16-22.
    [3]史玉胜,何世明,林文秀,等.微流量控压钻井技术研究现状[J].钻采工艺,2011,34(3):12-14.SHI Yusheng,HE Shiming,LIN Wenxiu,et al.Research on micro-flux control pressure drilling technologh[J].Drilling&Production Technology,2011,34(3):12-14.
    [4]李之军.垂直裂缝地层气液置换及钻井液防气侵封堵技术研究[D].西南石油大学,2014.LI Zhijun.Study on gas liquid replacement in vertical fracture layer and gas intrusion sealing technology of drilling liquid[D].Southwest Petroleum University,2014.
    [5]刘绘新,李锋.裂缝性储层井控技术体系探讨[J].天然气工业,2011,31(6):77-80.LIU Huixin,LI Feng.Well control technologies for fractured gas reservoirs[J].Natural Gas Industry,2011,31(6):77-80.
    [6]WARPINSKI N R,MAYERHOFER M,AGARWAL K,et al.Hydraulic-Fracture Geomechanics and MicroseismicSource Mechanisms[J].SPE Journal,2012,18(18):766-780.
    [7]陈守坤,李希建.基于Fluent-tecplot的穿层抽采钻孔周围煤体瓦斯流动模拟研究[J].煤炭技术,2012,31(5):78-80.CHEN Shoukun,LI Xijian.Simulation research of gas flow in coal surrounding drainage crossing hole based on Fluent-tecplot[J].Coal Technology,2012,31(5):78-80.
    [8]袁智,汪海阁,葛云华,等.含硫天然气气侵方式研究[J].石油钻采工艺,2010,32(2):46-50.YUAN Zhi,WANG Hai,GE Yunhua,et al.Research on modes of sour natural gas cut[J].Oil Drilling&Production Technology,2010,32(2):46-50.
    [9]李超.塔里木高含硫地区钻井井控安全研究[D].西安石油大学,2015.LI Chao.Study on the well control safety in high sulfur area of Tarim oilfield[D].Xi'an Shiyou Universty,2015.
    [10]WILLIAMS-STROUD S C,BARKER W B,SMITH K L.Induced hydraulic fractures or reactivated natural fractures modeling the response of natural fracture networks to stimulation treatments[J].SPE Journal,2012,30(7):221-234.
    [11]EZZEDINE S M.Coupling of Multiphase Flow and Geomechanics in Fractured Porous Media:Application to CO2 Leakages from Natural and Stimulated Fractures[C]//AGU Fall Meeting.AGU Fall Meeting Abstracts,2015.