中国石油勘探 ›› 2020, Vol. 25 ›› Issue (3): 107-120.DOI: 10.3969/j.issn.1672-7703.2020.03.010

• 石油地质 • 上一篇    下一篇

顺北地区走滑断裂与断溶体圈闭识别描述技术

李海英,刘军,龚伟,黄超,任丽丹   

  1. 中国石化西北油田分公司
  • 出版日期:2020-05-15 发布日期:2020-05-15
  • 基金资助:
    国家科技重大专项“海相碳酸盐岩地震勘探关键技术”(2017ZX05005-004);中国石化科技攻关项目“顺北特深断溶体 储集体地震关键技术研究应用”(P18040)。

Identification and characterization of strike-slip faults and traps of fault-karst reservoir in the Shunbei area, Tarim Basin

Li Haiying, Liu Jun, Gong Wei, Huang Chao, Ren Lidan   

  1. Sinopec Northwest Oilfield Company
  • Online:2020-05-15 Published:2020-05-15
  • Supported by:
     

摘要: 顺北地区奥陶系目的层主要发育洞穴型、裂缝型和孔洞型3 种类型储层,储层非均质性强,且储集规模 受多期活动走滑断裂体系控制。已钻井揭示的断溶体储层地震响应特征多样,预测与描述难度大。断溶体圈闭是一种 与喀斯特岩溶缝洞型圈闭有较大差异,在复杂条件下形成的特殊碳酸盐岩缝洞型圈闭,具有纵向跨越深度大、横向非 均质性强、不受局部构造形态控制、无统一油水界面、上覆区域泥岩顶封、致密碳酸盐岩可侧封的特点。在前期研究 认识基础上,通过模型正演,结合井震标定及地震反射特征分析,建立了走滑断裂、断控缝洞储集体地震识别模式, 形成了梯度结构张量定断溶体轮廓,振幅变化率、杂乱相属性等分类预测断裂带内部储层,多属性融合雕刻描述断溶 体的储层识别描述技术;建立了断溶体识别与圈闭描述技术。该技术的应用指导了顺北地区多口井部署并实现油气重 大突破,储层钻遇率达84%,证实了技术的有效性及适用性,为顺北油气田和其他地区识别及描述断溶体提供了解决 方法和技术参考,对顺北油田超深层领域断溶体勘探开发具有重要意义。

 

关键词: 顺北地区, 碳酸盐岩, 走滑断裂, 断溶体, 圈闭描述

Abstract: There are three principal types of reservoirs in the Ordovician objective strata in the Shunbei area: cave type, fracture type and vug type. Reservoir is characterized by strong heterogeneity and reservoir scale is controlled by strike-slip fault systems with multi-stage activities. The seismic response characteristics of fault-karst reservoirs penetrated by wells vary widely, which makes them difficult to predict and describe. Different from karst fracture-cavity trap, fault-karst reservoir trap is a kind of special carbonate fracture-cavity trap formed under complex conditions. It is characterized by large vertical range and strong horizontal heterogeneity. It is not controlled by local structural morphology and has no unified oil-water contact. Top sealing is provided by regional overlying mudstone, and lateral sealing can be provided by tight carbonate rocks. On the basis of previous research and understandings, seismic identification modes of strike-slip faults and fault-controlled fracture-cavity reservoirs have been established by the use of forward modeling, well-seismic calibration and seismic reflection characteristics analysis. Reservoir identification and description technologies have been formed using gradient structure tensor to determine the shapes of fault-karst reservoirs, using amplitude change rate and chaotic phase attributes to classify and predict interior reservoirs in fault zones, and using multi-attribute fusion to characterize and describe fault-karst reservoirs. Technologies for fault-karst reservoir identification and trap description have been established. The application of these technologies has guided the deployment of several wells in the Shunbei area, which have achieved major breakthroughs in oil and gas discovery. The penetration rate of reservoirs is 84%, which proves the validity and applicability of the technologies. This provides a solution and technical reference for identification and description of fault-karst reservoirs in the Shunbei Oil and Gasfield, as well as other areas, and is of great significance for the exploration and development of fault-karst reservoirs in ultra-deep formations in the Shunbei Oilfield.

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