水热增压作用与地层异常高压的关系探讨  

Relation of hydrothermal pressurization to abnormal high pressure

作　　者：周鹏高[1] 李亚双[2] 罗川[1] 徐艺侨 ZHOU Penggao;LI Yashuang;LUO Chuan;XU Yiqiao(Karamay Vocational&Technical College,Karamay,Xinjiang 834000,China;No.1 Oil Production Plant,PetroChina Xinjiang Oil-field Company,Karamay,Xinjiang 834000,China;Chongqing Yuchuan Gas limited liability company,Chongqing 400000,China)

机构地区：[1]克拉玛依职业技术学院,新疆克拉玛依834000 [2]中国石油新疆油田公司采油一厂,新疆克拉玛依834000 [3]重庆市渝川燃气有限责任公司,重庆400000

出　　处：《天然气技术与经济》2023年第3期32-35,66,共5页Natural Gas Technology and Economy

基　　金：新疆维吾尔自治区自然科学基金“欠压实作用形成异常高压机理及定量评价方法研究”(编号:2021D01A28)。

摘　　要：异常高压的成因机制是石油地质学的重要研究内容,水热增压作用能否成为异常高压的有效成因机制是一个尚未解决的学术难题。为了定量评价水热增压作用对地层压力及压力系数的影响,根据岩石及流体的热物理学原理,分析了水热增压作用产生的前提条件,建立了水热增压作用下地层压力及压力系数的定量评价模型,探讨了水热增压作用与地层异常高压的关系。研究结果表明:(1)水热增压作用产生的条件是地层封闭且埋深增大;(2)评价水热增压作用对地层压力的影响时需要排除欠压实作用的影响;(3)地层深度增量一定时,地温梯度和地层流体热膨胀系数越大,岩石的热膨胀系数和地层流体的压缩系数越小,地层压力增量以及压力系数就越大;(4)在可钻深度范围内,温度升高引起的流体体积应变一般不会超过2%;(5)一方面,水热增压作用能使地层压力快速增大,另一方面,由于地层深度相应增大,地层压力系数的变化很小,压力系数增量一般不会超过0.1,单一的水热增压作用不能形成异常高压。Origin mechanisms on abnormal high pressure are fundamental contents in petroleum geology.Whether hydro-thermal pressurization is one of effective mechanisms is still an unsolved academic problem.So,preconditions to cause the pressurization were analyzed according to thermal physical principles of rock and fluid in order to quantitatively evaluate pressurization effects on formation pressure and pressure coefficient.Then a model to quantitatively assess both formation pressure and pressure coefficient was established in the context of hydrothermal pressurization.Additionally,one relation of hydrothermal pressurization to abnormal high pressure was discussed.Results show that(i)there emerge two conditions in the pressurization,such as strata in enclosure and their increased burial depth;(ii)it is essential to exclude an undercom-paction effect when evaluating the pressurization impact on formation pressure;(iii)at a fixed increase of burial depth,the greater the geothermal gradient and the thermal expansion coefficient of formation fluid,the lower the thermal expansion co-efficient of rock and the compression coefficient of formation fluid,and the greater the formation pressure increase and the pressure coefficient;(iv)in the range of reach-extended depth,the strain of fluid volume induced by rising temperature is generally less than 2.0%;and(v)on the one hand,the hydrothermal pressurization may lead to rapid increase in formation pressure.On the other hand,given formation depth adds correspondingly,the formation pressure coefficient changes a little with the coefficient increment generally no more than 0.1.To sum up,only hydrothermal pressurization cannot grow up ab-normal high pressure.

关 键 词：水热增压 异常高压 地层压力 压力系数 定量评价 

分 类 号：P618.13[天文地球—矿床学]