物性结构差对9点井网排状加密前后影响研究

A Study on the Influence of Property Structure Before and After the 9-point Well Pattern Arrangement

熊钰 刘成 周文胜 刘晨 钟浩

XIONGYu LIUCheng ZHOUWensheng LIUChen ZHONGHao

西南石油大学石油与天然气工程学院, 四川 成都 610500 中海油研究总院有限责任公司, 北京 朝阳 100027

Petroleum Engineering School, Southwest Petroleum University, Chengdu, Sichuan 610500, China CNOOC Research Institute Co. Ltd., Chaoyang, Beijing 100027, China

通过大尺度岩芯实验，测试了从均质到多层非均质岩芯九点井网到排状加密下物性结构差导致的压力结构差时变曲线，结合岩芯三维空间含油饱和度时变检测结果，详细研究了受物性结构差和压力结构差双重影响下的水驱动用变化规律和特点及流场演变和剩余油分布变化特征。结果表明，从大段均质到层间非均质，高渗透层压力变化缓和、压降较小，低渗透层压力降幅较大，层间压差达到3 MPa，高渗透层和低渗透层水驱控制程度相差14%，而从层间非均质到层内非均质模型，各层井间非均质性导致主流线绕流多变，水驱前缘难以规整有效推进，非均质程度越严重的层位，水驱动用程度越低，压力降幅相对越大；在井网加密调整后，排状注水驱替使得水驱前缘相对平行推进，显著改善井间压力和非均质性产生的平面矛盾，纵向上层间压差逐渐消失，层间矛盾得以缓解，两类非均质模型水驱动用程度提高30%左右，但对于非均质程度较强的储层，大范围低渗带的存在依然是剩余油主要富集区域。

In the study, through the large-scale core experiment, the pressure structure time-varying curve caused by the difference of the physical structure from the homogeneous core to the multi-level heterogeneous core nine-point well network to the row-like encryption is tested. Combined with the time-varying test results of three-dimensional oil saturation in core, the variation law and characteristics of water drive under the double influence of physical structure difference and pressure structure difference are studied in detail, including characteristics of flow field change and remaining oil distribution are discussed. The results show that from large homogenization to interlayer heterogeneity, the pressure of high permeability layer is moderate, the pressure drop is small, and the pressure drop of low permeability layer is large, and the pressure difference between layers is 3 MPa, high permeability layer and low. The degree of water flooding control in the permeable layer differs by 14%. From the interlayer heterogeneity to the intralayer heterogeneity model, the heterogeneity between the wells leads to variable flow around the main flow line; the front edge of the water drive is difficult to regulate and promote effectively; the more serious the degree of heterogeneity, the lower the degree of water drive, the greater the pressure drop. After the well network encryption adjustment, the drainage of water discharge pushes the water-driven front edge in parallel, which significantly improves the plane contradiction between the pressure and heterogeneity between the wells. The pressure difference between the vertical and the upper layers gradually disappears, and the inter-layer contradiction is alleviated. The degree of water driving of the two types of heterogeneous models is improved by 30%, but for reservoirs with strong heterogeneity, the existence of large-scale low-permeability zones is still the main enrichment area of remaining oil.

10.11885/j.issn.1674-5086.2019.10.04.02