川东北地区须家河组“断缝体”气藏立体雕刻技术及应用

四川盆地东北部须家河组发育致密砂岩气藏, “断缝体”概念的提出有效提升了该类型气藏的勘探开发效果, 但对“断缝体”的主控因素以及三维空间形态尚缺乏清晰认识, 制约了该技术的进一步推广与应用。利用马路背-通江地区高精度OVT地震资料, 联合地质-地球物理多学科协同的配套预测技术方法, 遵循“断缝体”气藏地质特征及高产稳产主控因素, 开展了断褶变形强度带量化评价、缝孔储层预测、通源断裂体系评价等相关研究。并以此3个要素为基础, 联合构建了断缝结构、缝孔储层以及通源断层三元一体化立体模型, 探索形成了一套“断缝体”立体雕刻技术方法。该技术精细雕刻了“断缝体”各单元空间形态与内部结构, 并清晰直观表达了各成藏要素的多维配置关系, 为须家河组“断缝体”气藏进一步精细化勘探开发提供了技术支撑, 同时也为其它类似地区“断缝体”油气藏的刻画识别提供了参考。

Tight sandstone gas reservoirs are developed in the Xujiahe Formation in the northeastern Sichuan Basin.The presence of "fault-fracture reservoirs" contributes to the effective exploration of these types of gas reservoirs.However, the main factors regulating the formation of the fault-fracture reservoirs, as well as the three-dimensional spatial configuration, remain poorly understood, limiting further promotion and application.On the basis of the high-resolution OVT seismic data of the Malubei-Tongjiang area and geological characteristics of the fault-fracture reservoirs, which were combined with the geologically- or geophysically-based prediction technologies, a series of studies were conducted to quantitatively evaluate the fault-fold belt strength, fracture-pore reservoir prediction, and through source fault system.The fault-fold belt strength is controlled by fault strength, fault density, and fold strength.Micro fractures and sedimentary facies regulate the formation of the fracture-pore reservoir.The through source fault system is dominated by the thickness of gypsum salt rock and the configuration relationship between faults above and below the salt.Based on the three factors listed above, a three-element-integrated "fault-fracture reservoir" model with a fracture structure, fracture-pore reservoir, and through source fault was developed.Thus, a three-dimensional carving technology for "fault-fracture reservoirs" was created.This technology clearly illustrates the spatial morphology and internal structure of each unit of the "fault-fracture reservoirs", as well as the multi-dimensional configuration relationship of the gas accumulation elements, providing technical support for further fine exploration and development of fault-fracture gas reservoirs of Xujiahe formation.This research will also aid in the characterization and identification of "fault-fracture reservoirs" in other similar areas.