地球物理学进展 ›› 2017, Vol. 32 ›› Issue (6): 2581-2588.doi: 10.6038/pg20170639

• 应用地球物理学Ⅰ • 上一篇    下一篇

砂岩储层压实过程中孔隙度演化的定量分析

张创1, 罗然昊1, 高辉2, 周雪1, 王成龙1   

  1. 1. 延长油田股份有限公司志丹采油厂, 陕西延安 717500;
    2. 西安石油大学石油工程学院, 西安 710065
  • 收稿日期:2017-04-04 修回日期:2017-09-24 出版日期:2017-12-20 发布日期:2017-12-20
  • 通讯作者: 罗然昊,男,1972年生,湖北钟祥人,硕士,高级工程师,现从事开发地质和精细注水研究工作.(E-mail:1419592269@qq.com) E-mail:1419592269@qq.com
  • 作者简介:张创,男,1981年生,陕西渭南人,博士,高级工程师,现从事储层评价与油田开发研究工作.(E-mail:zhangchuang530@126.com)
  • 基金资助:

    自然科学基金项目(41102081)资助.

Quantitative analysis of porosity evolution in compacting process of sandstone reservoirs

ZHANG Chuang1, LUO Ran-hao1, GAO Hui2, ZHOU Xue1, WANG Cheng-long1   

  1. 1. Zhidan oil Production Plant, Yanchang Oil Field Company Limited, Shanxi Yan'an 717500, China;
    2. College of Petroleum Engineering, Xi'an Petroleum Institute, Xi'an 710065, China
  • Received:2017-04-04 Revised:2017-09-24 Online:2017-12-20 Published:2017-12-20

摘要:

砂岩储层压实过程中孔隙度的变化规律,是成岩数值模拟与储层质量预测的核心研究内容之一.通过对前人提出的孔隙度表征参数与压实强度表征参数进行分析、甄别,对压实过程中孔隙度变化规律进行研究,建立了三类不同砂岩类型储层的孔隙度压实方程.结果表明,粒间体积百分比(粒间孔隙度、胶结物含量与杂基含量之和)与埋藏过程中骨架颗粒所承受的最大有效应力在描述压实减孔规律时具有明显的优势.压实过程中孔隙度的减小具有分段性,表现为较浅埋藏期的快速递减与较深埋藏期的缓慢递减或恒定不变,二者可用一个统一方程描述.压实方程中的常数β与砂岩中塑性颗粒的含量及其塑性级别有关,随塑性颗粒含量提高及其塑性增强,β值增大;刚性颗粒组成的砂岩储层β为0.058 MPa-1,含75%极高塑性岩屑的砂岩储层β高达0.146 MPa-1.建立的压实方程在三类不同砂岩类型储层的应用中,绝对误差最大3.1%,相对误差最大13.8%,取得了良好的效果.

Abstract:

The characteristics of porosity evolution in compacting process of sandstone reservoirs, are main research contents of diagenesis numerical simulation and reservoir quality predicting. By analyzing and identifying the parameters of porosity and compaction intensity, I studied the rule of varying porosity in the process of compaction and established equations in three types of sandstone reservoir. The results show that, the method that considering IGV as porosity characteristic parameters in the process of compaction and considering the maximum effective stress of skeleton particle as compaction strength characteristic parameters in the process of burial is more reasonable. IGV (Intergranular volume, which is the sum of intergranular pore space, intergranular cement, and depositional matrix) and maximum effective stress are chosen to establishing function. There are two phases of porosity decrease in compacting process, which are quick decrease in shallow burial depth and slow decrease or constant in deep burial depth, and the two phases can be expressed in a unified equation. IGVf can be obtained through thin section analysis. IGVo can be obtained by beard's artificial core experimental results based on the known sandstone structure. The effective stress of skeleton particle can be identified by overburden pressure and formation pressure based on burial history reconstruction. The constant β in the equation, is controlled by content and ductility of ductile grains in sandstones, being 0.058 MPa-1 in rigid-grain sandstone,and 0.146 MPa-1 in sandstone with 75% extremely ductile grains. The application of the equation in three reservoirs with different sandstone classifications, is satisfactory with 3.1% absolute error and 13.8% relative error. The optimum selection of compaction parameter, the establishment of compaction equations and the determination of various parameters in equation are based on the previous research results. The maximum effective stress influenced by multiple factors in the process of compaction, although we obtained satisfactory results from the three different types reservoir examples. This article discusses relationship between effective stress and porosity evolution,Only under ideal conditions that the formation is not obvious overpressure or low-pressure, with vertical effective stress decided by overburden pressure are assumed to be the maximum stress.

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