摘要
断控缝洞型碳酸盐岩油藏受大型克拉通内走滑断裂控制和改造,其纵向多发育为断裂复合储层体(裂缝-溶洞体),该储集体既是油气运移通道,又是储层空间,其空间及配置关系复杂.为实现注水开发过程中油水界面和见水规律的准确分类及预测,并提供后续开发方案和对策指导,以单一溶洞下的油水界面运移特征为基础,利用物质平衡方程建立一种新的断控缝洞型油藏多溶洞连通下的油水运移数学模型,基于稳态逐步替换法形成了注采井间动态油水界面实时追踪预测方法.与常规数值模拟方法相比,该模型构建简易,计算效率高,综合考虑了油水密度差异和井-裂缝-溶洞间的复杂纵向配置关系,能够较为准确预测生产井的见水规律、各溶洞油水界面运移位置及剩余油分布等各项开发指标.研究结果表明,多缝洞开发单元受生产制度和缝-洞储层参数影响,油井生产期将出现3个阶段(纯油、油水同产和纯水期);合理的采油速度与注水量可有效保持地层压力,兼顾采出程度和裂缝应力敏感效应;裂缝传导率越高,储层能量恢复越快,油水界面上升也变快;随着注采井间溶洞体积及裂缝传导率差异增大,油水同产期将变长.最后,对比Eclipse数值模拟器与本研究模型计算结果,分析溶洞体物性参数(渗透率和孔隙度)对油水界面运移速度的影响.鉴于目前断控缝洞型油藏地质构造及裂缝-溶洞体配置关系的多样性,开展多井生产动态与模型预测结果的实时拟合工作是目前油水界面评价与追踪的有效方法.本研究模型为断控缝洞型油藏见水预警、注采参数优化及剩余油挖潜对策制定提供了基础理论与方法.
Fracture-controlled fracture-vuggy carbonate reservoirs are governed by extensive scale slip fracture modification within the craton and the longitudinal development of fracture-composite reservoir body(fracture-cavern body),which serves as both a channel for oil and gas transportation and reservoir space,exhibiting intricate spatial and configurational interdependencies.At present,there is no reasonable model to realize the precise classification and prediction of oil-water interface and water breakthrough rule during waterflood development,along with the formulation of subsequent development strategies and mitigative measures to address the existing predicament.In this study,based on the oil-water interface transport characteristics under a single cavern,a novel mathematical model of oil-water transport under multiple cavern connectivity in fault-controlled fracture-vuggy reservoirs is established by using the material balance equation.Furthermore,a real-time tracking and prediction approach for the dynamic oil-water interface between injection and extraction wells is devised based on the steady-state stepwise substitution method.In contrast to traditional numerical simulation approaches,this model is straightforward to formulate,remarkably efficient,and considers variations in oil-water density,as well as the intricate longitudinal arrangement of well-fracture-cavity systems.Consequently,it enables precise forecasting of water pattern of the production wells,the location of the oil-water interface in the cavities,and the distribution of residual oil and other development indexes.The results of the study show that multi-seam cavern development unit is affected by the production system and seam-cave reservoir parameters,and there will be three phases of well production(pure oil,oil-water co-production,and pure water period).Reasonable oil recovery and injection water rate can effectively maintain the formation pressure,balancing production efficiency and fracture stress sensitivity.As fracture conductivity increases,reservoir energy recovery accelerates,leading to a more rapid ascent of the oil-water interface.Furthermore,with the increase of cavern volume and fracture conductivity difference between injection and extraction wells,the oil-water co-production period will become longer.Finally,this paper compares the difference between the results of Eclipse numerical simulator and the calculation results of the model in this paper,and analyzes the influence of the physical parameters of the cavern body on the transport speed of the oil-water interface.In view of the current geological structure of fault-controlled fracture-vuggy reservoirs and the diversity of fracture-cavern body configuration relationships,it is an effective method to carry out real-time fitting of production dynamics of multiple wells with the results of the model prediction for the assessment and continual tracking of the oil-water interface.The proposed model provides a theoretical foundation and methodology for early warning of water breakthrough,optimization of injection and recovery parameters,and formulation of countermeasures for residual oil recovery in fault-controlled fracture-vuggy reservoirs.
作者
王远征
曹仁义
贾品
WANG Yuanzheng;CAO Renyi;JIA Pin(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,P.R.China;College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,P.R.China)
出处
《深圳大学学报（理工版）》
CAS
CSCD
北大核心
2024年第2期152-162,共11页
Journal of Shenzhen University(Science and Engineering)
基金
国家自然科学基金资助项目(21075138)。
关键词
油田开发
断控缝洞型油藏
碳酸盐岩
见水预警
注采参数优化
生产动态
缝洞配置关系
oil field development
fault-controlled fracture-vuggy reservoirs
carbonate rock
flood warning
injection and production parameters optimization
production performance
configuration relationship
