冯沙沙 1戴建文 2徐辉 2李黎 2刘思雨 2吴克柳3
作者信息
- 1. 中国石油大学(北京)石油工程学院,北京 102249||中海石油(中国)有限公司深圳分公司,广东 深圳 518000||中海石油深海开发有限公司,广东 深圳 518000
- 2. 中海石油(中国)有限公司深圳分公司,广东 深圳 518000||中海石油深海开发有限公司,广东 深圳 518000
- 3. 中国石油大学(北京)石油工程学院,北京 102249
- 折叠
摘要
Abstract
The ZJ10A and ZJ10B formations of the L Oilfield in the Pearl River Mouth Basin are the main low-permeability reef limestone reservoirs.The average measured core permeability of the two limestone reservoirs,A and B,in the ZJ10 layer is 45.9 mD,with a median value of 21.5 mD.The reservoirs are characterized by strong heterogeneity and well-developed fractures.In the early stage of oilfield development,problems such as rapid water breakthrough,significant production decline,and energy depletion were encountered.As the first water-flooded fractured low-permeability reef limestone oilfield in the eastern South China Sea,it has low well-pattern density,few coring intervals,and insufficient imaging logging data.With traditional methods,it is difficult to accurately characterize small-scale inter-well fractures.The main controlling factors and development patterns of fractures are unclear,which restricts the efficient development of the reservoir.To address the above difficulties,guided by reservoir geomechanics theory,this paper integrates multi-source data and constructs an integrated technical system of"paleo-petrophysical parameter correction-in-situ stress simulation-fracture prediction-development countermeasures".Based on the background of the Dongsha movement,the paleo-burial depth(600～700 m shallower than the present)was restored,and the paleo-petrophysical parameters were obtained by correcting the present logging data.Finite element numerical simulation was adopted,with a 33 MPa northwestward paleo-stress applied to quantify the controlling effect of stress on fractures.The reliability of the prediction results was verified using the fracture development is only enhanced at image logging and actual drilling data.The results show that the target reservoirs are mainly developed with two sets of high-angle conjugate shear structural fractures(accounting for 91%)trending northwest and nearly north-south,whose formation is controlled by the north-westward compressive stress during the Dongsha Movement.Laterally,the high fracture development areas are concentrated in the structural highs in the east of Well 1d and the south of Well 2d,and the fracture development is only enhanced at the turning points of the southern fault.Vertically,the fracture density of the ZJ10A formation(0.13～0.31 fractures/m)is higher than that of the ZJ10B formation(0.04～0.28 fractures/m),and it decreases from top to bottom.The fracture prediction results were verified by actual drilling data,with the absolute error of 82%of the samples being≤0.7 fractures/m,indicating reliable prediction.Meanwhile,there was a positive correlation between the fracture density and the water cut rise rate in the early production stage.Based on this,the production wells were divided into 4 types,and corresponding oil stabilization and water control measures were proposed for each type.The integrated technical process constructed in this study effectively solved the problem of quantitative prediction of small-scale fractures in low-permeability reef reservoirs under the condition of few actual measurement data.The study indicates that the constructed integrated technical system effectively solves the problem of quantitative prediction of small-scale fractures in low-permeability reef limestone under the condition of few offshore wells and improves the relevant technical system.The clarified fracture distribution patterns and differentiated oil stabilization and water control countermeasures for the 4 types of wells can provide a scientific basis for the development adjustment of the L Oilfield and also provide technical reference for the fine exploration and efficient development of similar reservoirs at the Sea.关键词
低渗/礁灰岩/裂缝精细表征/开发效果/稳油控水Key words
low permeability/reef limestone/fine fracture characterization/development effect/oil stabilization and water control分类
天文与地球科学
