多期构造应力控制走滑断控储层发育机理与差异性研究——以塔里木盆地顺北地区为例

Study on development mechanism and variability of strike-slip fault-controlled reservoirs regulated by multi-stage structural stress: a case study of the Shunbei area, Tarim Basin

张继标 邓尚 韩俊 李映涛 刘大卫 邱华标 张仲培 刘雨晴

ZHANG Jibiao DENG Shang HAN Jun LI Yingtao LIU Dawei QIU Huabiao ZHANG Zhongpei LIU Yuqing

1. 中国石化 石油勘探开发研究院, 北京 100083; 2. 中国石化 西北油田分公司, 乌鲁木齐 830011

1. SINOPEC Petroleum Exploration and Production Research Institute, Beijing 100083, China; 2. SINOPEC Northwest Oilfield Company, Urumqi, Xinjiang 830011, China

塔里木盆地顺北油气田发育典型走滑断控缝洞型储层。区别于受原始沉积相带控制的基质孔洞、受岩溶改造的洞穴等储集类型，走滑断控缝洞型储层的形成主要受断裂活动期构造应力导致的破裂作用控制。为研究走滑断裂多期活动背景下构造应力控制的断控储层发育机理与分布规律，综合应用野外、岩心、测录井、地震及钻井动态等资料，开展不同走滑断裂、同一走滑断裂沿走向不同部位、垂向不同层系断控储层发育特征表征，并结合应力场数值模拟手段开展多期构造应力恢复，预测断控储层发育的主要时期与分布规律。结果表明，走滑断裂活动期不同分段内部应力状态差异显著，其中拉分段内部以张应力为主，主要派生张性裂缝；压隆段内部以挤压应力为主，派生裂缝类型多样。顺北地区勘探目的层奥陶系一间房组顶面断控裂缝主要在加里东中期Ⅲ幕及加里东晚期—海西早期发育，海西中—晚期及之后裂缝基本不发育，且滑移距大的顺北18号断裂带较顺北1号断裂带派生裂缝开度、密度更高。走滑断控储层具有“簇状”结构特征，断裂活动期不同分段内部应力状态控制储层结构差异，拉分段“空腔”多，以“双簇”结构为主，核带规模大，压隆段核带结构多，以“多簇”结构为主，分割性强；走滑断裂活动期应力强度控制储集空间类型与规模，小型断裂储集空间以裂缝为主，大型断裂带发育核带结构，断控储层规模与断裂活动强度呈正相关关系；断控裂缝发育主要受断裂早期活动控制，晚期由于地层埋深增大，岩石不易破裂，新派生裂缝发育较少。

The Shunbei oil-and-gas field in the Tarim Basin features a typical strike-slip fault-controlled fractured-vuggy reservoir. The formation of these reservoirs is primarily influenced by fracturing related to structural stress during periods of fault activity. This contrasts with reservoir types such as matrix vugs controlled by original sedimentary facies and caves modified by karst. To study the development mechanism and distribution patterns of strike-slip fault-controlled reservoirs under the influence of multi-stage structural stress, comprehensive analysis of field observations, core samples, well logging data, seismic surveys, and drilling dynamic data was conducted to characterize the development characteristics of fault-controlled reservoirs. This included different strike-slip faults, different parts along a single strike-slip fault, and different stratigraphic levels vertically. Combined with stress field numerical modeling, multi-stage structural stress recovery was carried out to predict the main development periods and distribution patterns of fault-controlled reservoirs. Significant variations in internal stress states were observed across different segments during periods of strike-slip fault activity. Tensile stress predominated in pull-apart segments, resulting in predominantly tensile fractures, whereas compressional stress state in push-up segments led to a variety of fracture types. The fault-controlled fractures in the top of the Yijianfang Formation in the Shunbei area were mainly developed during episode Ⅲ of the Middle Caledonian period and the Late Caledonian-Early Hercynian period. Few fractures were developed during the Middle to Late Hercynian period and thereafter. Compared to the Shunbei No.1 fault, the Shunbei No.18 fault exhibited higher fracture opening degree and density with a large displacement. Strike-slip fault-controlled reservoirs exhibit a cluster-like structure. Structural differences of the reservoirs are influenced by internal stress states in different segments during fault activity. Pull-apart segments typically feature a large fault core-damage zone with more cavities and ‘double-cluster’ structures, whereas push-up segments display more diverse fault core-damage zones with greater separability and ‘multi-cluster’ structures. The stress intensity during the strike-slip fault activity controls the types and scale of reservoir spaces, with smaller fault zones dominated by fractures and larger fault zones developing extensive fault core-damage zone architectures. The scale of fault-controlled reservoirs is positively correlated with fault activity intensity. Early fault activity promotes significant fracture development, while later stages, characterized by increased burial depths, result in few newly derived fractures due to reduced rock susceptibility to fracturing.

国家自然科学基金(U21B2063、42330812)和中国石化科技部项目(P24077、P24173)联合资助。

https://doi.org/10.11781/sysydz202404775