Title

Application of carbonate fracture characterization to water-cut performance in oilfield M

单位

中国海洋石油国际有限公司海外技术支持中心,北京 100028

Organization

Overseas Technical Support Center of CNOOC International Limited,Beijing 100028,China

摘要

M油田为陆上推覆构造背景下的白垩系厚碳酸盐岩储层。复杂的生产历史及微裂缝的发育导致水淹规律比较复杂,因而在后续开发方案动态调整中,需要准确判别开发过程中水淹规律以及水进趋势。利用三维地震多方位角数据分析预测储层裂缝,结合目标地层构造形态与受力变形特征,分析地层裂缝参数以及应力场空间分布,研究储层裂缝发育特征,综合解释碳酸盐岩油藏内部流体运移方向与水驱强弱关系,判别开发过程中油田的水淹规律以及水进趋势。生产动态分析表明,目标储层内注入水流动趋势和水驱速度主要受井点周边的裂缝发育程度和裂缝方向控制。基于对地震各向异性和构造应力场的综合裂缝分析研究,明确了目标层段的裂缝发育强弱、裂缝方向和裂缝联通特征,对各个注水井的不同效率做了进一步解释。如果注水井位于裂缝不发育的区域或水进与裂缝方向垂直,水驱速度则比较稳定,周边受效井效果比较好;反之,受效井含水上升就比较快。裂缝发育特征与含水动态关联分析为后续井位的调整与开发方案的优化提供了具体指导。

Abstract

Oilfield M is a thick Cretaceous carbonate reservoir with onshore nappe structures.The complexities of production history and microcracks lead to complicated water-flooding patterns.Therefore,it is necessary to accurately identify water-flooding pattern and water transgression in the production for the dynamic adjustment of subsequent development plan.Based on fracture prediction using 3D multi-azimuth seismic data and tectonic features and deformation in the interval of interest,we investigate fracture parameters and spatial distribution of stress field and interpret the relationship between fluid migration direction in carbonate reservoirs and the intensity of water flooding to diagnose water-flooding patterns and water transgression in the process of oilfield development.As per production performance,injected water flow and water flooding velocity in the reservoir are related to fracture density and orientation around the well.According to fracture analysis based on seismic anisotropy and tectonic stress field,we define fracture intensity,orientation,and connectivity in the interval of interest and explain waterflood efficiency discrepancies for different water injection wells.If the injection well is located in the area with small fracture density or water transgression perpendicular to fracture orientation,water flooding will go on at steady velocity and surrounding wells will be swept sufficiently.On the contrary,the water cut in the affected wells will rise quickly.The correlation between fractures and dynamic water cut could be used to guide drilling site adjustment and development plan optimization.

关键词：

碳酸盐岩; 地震各向异性; 裂缝; 构造应力场; 含水动态;

Keywords:

carbonate reservoir; seismic anisotropy; fracture; tectonic stress field; dynamic water cut;

基金项目

国家重大专项课题(2017ZX05032-003)和中海油有限公司综合科研项目(YXKY-2019-ZY-06)共同资助。

DOI

10.12431/issn.1000-1441.2024.63.04.014

M油田碳酸盐岩裂缝研究与含水动态分析