致密储层极限渗透率的计算及其应用  

Calculation and application of ultimate permeability for tight reservoirs

作　　者：刘志楠 张贵才[1] 葛际江[1] 杜勇[2] LIU Zhinan;ZHANG Guicai;GE Jijiang;DU Yong(School of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China;SINOPEC Shengli Oilfield,Dongying 257001,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]中石化胜利油田分公司,山东东营257001

出　　处：《中国石油大学学报(自然科学版)》2025年第1期136-144,共9页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：中国石油天然气集团有限公司科技计划专项(ZD2019-183-007-033)。

摘　　要：致密储层渗透率是决定水驱开发方式为驱替、渗吸或是驱替-渗吸联合使用的重要参数。分析不同渗透率下动态压差和渗吸压差的变化规律,提出致密储层极限渗透率的存在并对其定义,即极限渗吸渗透率(k_(i))、极限驱替渗透率(k_(d))和极限驱替开发渗透率(k_(u))。基于极限渗透率的定义,阐明各极限渗透率对于水驱的意义,提出一种计算水湿(弱水湿)致密储层k_(i)、k_(d)和k_(u)的方法,并对中国典型致密储层极限渗透率计算。结果表明:当渗透率降低至某一数值时,动态压差(渗吸压差)的数值变为零;渗吸动力在驱动力中的比例随储层渗透率降低而增加,而动态压差与渗吸压差随渗透率升高而增大;k_(i)是致密储层可采渗透率的下限,k_(d)是驱替开发渗透率的下限,k_(u)是驱替在开发过程起主导作用的渗透率下限;驱替-渗吸作用渗透率大于渗吸作用渗透率。The permeability of tight reservoirs is an essential parameter that determines whether the water flooding development mode is displacement,imbibition or a combination of displacement-imbibition.By analyzing the variation pattern of dynamic and static differential pressure at different permeability,the ultimate permeability was proposed to exist and defined,namely the ultimate imbibition permeability(k_(i)),the ultimate displacement permeability(k_(d))and the ultimate displacement development permeability(k_(u)).Based on the definition of ultimate permeability,the significance of each ultimate permeability for water flooding for water-wet(weakly water-wet)tight reservoirs was elucidated,and a method for calculating k_(i),k_(d) and k_(u) was proposed as well.And the ultimate permeability of typical tight reservoirs in China was calculated.The results indicate that the permeability decreases to a certain value,the value of the dynamic pressure difference(imbibition pressure difference)becomes zero.The proportion of imbibition dynamic force relative to the driving force increases as reservoir permeability decreases,while the dynamic pressure difference and the imbibition pressure difference increase with increase of permeability.k_(i) represents the lower limit of recoverable permeability in tight reservoirs,k_(d) denotes the lower limit of permeability for effective displacement development,and k_(u) indicates the lower limit of permeability where displacement becomes the dominant mechanism in the development process.The permeability of displacement-imbibition effect is greater than that of imbibition.

关 键 词：致密储层 极限渗透率 渗吸 驱替 驱替-渗吸 水驱开发 

分 类 号：TE122.2[石油与天然气工程—油气勘探]