摘要
目前,被普遍接受的煤层气工作流体储层伤害评价指标是渗透率变化值,其常用的渗透率测试方法多达6种,尚未见到采用实际测量方法对比研究6种测试方法适用性的成果报道。为此,在实验室内采用恒压法、恒流量法、岩屑脉冲衰减法、柱塞脉冲衰减法、压力振荡法和核磁共振法等6种方法,随机选取3组沁水盆地15号煤平行样品,对其在钻井液和压裂液伤害前后的渗透率进行测定,计算储层伤害前后的渗透率平均值和绝对储层伤害、相对储层伤害数据,进而采用简单排序法、一阶减元等序统计算法和测试原理分析法处理分析上述数据,通过绝对储层伤害和相对储层伤害排位的稳定性筛选适用的测试方法。研究结果表明:(1)恒压法和恒流量法实测的绝对储层伤害结果偏大,岩屑脉冲衰减法、柱塞脉冲衰减法和压力振荡法实测的结果偏小,核磁共振法实测的结果居中;(2) 6种方法实测的相对储层伤害分布无明显规律;(3)在煤层气储层伤害评价时,渗透率测试方法优先选择顺序为:岩屑脉冲衰减法>恒流量法>核磁共振法>柱塞脉冲衰减法=压力振荡法=恒压法,这是由各种方法的测试机理所决定的。结论认为:(1)岩屑脉冲衰减法最适合用于测试煤层气储层基质的伤害程度,恒流量法最适合测量整体的伤害程度;(2)煤层气工作流体储层渗透率伤害程度室内评价适宜并行使用岩屑脉冲衰减法和恒流量法。
Currently,permeability change is a widely-accepted evaluation index for CBM reservoir damage caused by working fluids.There are six common permeability testing methods.However,there have been no reports on the applicability of these methods based on the comparative investigation by means of actual measurement.In this paper,three groups of parallel samples of No.15 coal in the Qinshui Basin were selected randomly.Their permeabilities before and after being damaged by drilling and fracturing fluids were tested in the laboratory using the six methods,i.e.,A.constant pressure method,B.constant flowrate method,C.cutting pulse-decay method,D.plunger pulse-decay method,E.pressure oscillation method and F.nuclear magnetic resonance(NMR)method.Then,the average permeabilities before and after reservoir damage and the absolute and the relative reservoir damage were calculated and subsequently processed and analyzed using simple ranking method,element-reduced statistical screening algorithm and test principle analysis method.Finally,the suitable test method was screened out based on the ranking stability of absolute and relative reservoir damages.And the following research results were obtained.First,the absolute reservoir damage rates tested by the methods A&B are higher,those tested by the methods C,D&E are lower,and those tested by the method F are moderate.Second,as for the relative reservoir damage rates tested by the above-mentioned six methods,there is no obviously regular distribution pattern.Third,the application priority of the six permeability measurement methods for CBM reservoir damage evaluation is:C>B>F>D=E=A,which is determined by their test mechanisms.In conclusion,the method C is most suitable for testing the damage degree of CBM reservoir matrix,while the method B is for overall damage degree.And it is suitable to apply the methods B&C in parallel to the laboratory evaluation of the CBM reservoir permeability damage degree caused by working fluids.
作者
郑力会
李秀云
苏关东
赵炜
巩旭光
陶秀娟
Zheng Lihui;Li Xiuyun;Su Guandong;Zhao Wei;Gong Xuguang;Tao Xiujuan(State Key Laboratory of Petroleum Resources and Prospecting//China University of Petroleum,Beijing 102249,China;Sinopec Research Institute of Petroleum Engineering,Beijing 100101,China;Key Laboratory of Comprehensive Research and Application of Chemical Plugging Materials,Chemical Industry and Engineering Society of Hebei//Beijing LihuiLab Energy Technology Co.,Ltd.,Beijing 102200,China;Shaanxi University of Science and Technology,Xi'an,Shaanxi 710021,China)
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2018年第9期28-39,共12页
Natural Gas Industry
基金
国家科技重大专项“大型油气田及煤层气开发--多气合采钻完井技术和储层保护”(编号：2016ZX05066002-001)。
关键词
煤层气
储层伤害
渗透率
评价方法
适用性
钻井液
压裂液
算法
沁水盆地15号煤
Coalbed methane
Permeability
Reservoir damage
Evaluation method
Applicability
Drilling fluids
Fracturing fluids
Algorithm
No.15 coal of Qinshui Basin
