渤海海域渤中19-6构造带深层潜山储层特征及其控制因素

渤海海域渤中19-6构造带深层潜山储层特征及其

控制因素

侯明才1,2　曹海洋1,2　李慧勇3　陈安清1,2　韦阿娟3

陈扬1,2　王粤川3　周雪威1,2　叶涛3

1.“油气藏地质及开发工程”国家重点实验室•成都理工大学

2.成都理工大学沉积地质研究院

3.中海石油（中国）有限公司天津分公司

摘　要　渤海湾盆地渤中凹陷西南部的渤中19-6深层潜山构造带是新近勘探发现的特大型含油气区，该区的储层研究尚处于起步阶段，对储层发育特征及其控制因素的认识还不够深入。为此，基于对钻井岩心、井壁岩心、岩石薄片的观察和描述，结合区域构造背景、录井及测井等资料，对该区潜山储层的岩石学特征、储集空间类型、物性特征等进行分析，探讨控制储层发育的内在因素，研究储层展布规律。结果表明：①渤中19-6构造带深层潜山储层是由太古界潜山变质花岗岩主体及上覆的古近系古新统—始新统孔店组砂砾岩组成的泛潜山储集系统，形成砂砾岩孔隙带＋风化壳溶蚀裂缝带＋内幕裂缝带的多层次储层结构，储层成因复杂、类型多样；②太古界变质花岗岩潜山储集体内部在垂向上可划分为风化壳、内幕裂缝带和致密带，具有孔隙型和裂缝型的双重特性；③潜山风化壳主要受到强烈的溶蚀淋滤作用叠加断裂作用的影响，形成裂缝—孔隙型储集空间，内幕裂缝带储层的发育规模与分布受控于3期裂缝的叠加作用，燕山期以来是潜山裂缝的主要发育时期；④孔店组砂砾岩为典型的筛积沉积，后期溶蚀作用为其主要的控制因素；

⑤混合岩化作用及超临界流体隐爆作用对储层发育起到了建设性作用。结论认为，渤中19-6构造带发育砂砾岩＋变质岩潜山储集系统的认识，有助于确定该区下一步油气勘探的目标与方向。

关键词　渤海湾盆地　渤海海域　渤中19-6潜山构造带　太古代　深层变质花岗岩储层　古近纪　砂砾岩储层　溶蚀作用　构造裂缝

DOI: 10.3787/j.issn.1000-0976.2019.01.004

Characteristics and controlling factors of deep buried-hill reservoirs in

the BZ19-6 structural belt, Bohai Sea area

Hou Mingcai1,2, Cao Haiyang1,2, Li Huiyong3, Chen Anqing1,2, Wei Ajuan3,

Chen Yang1,2, Wang Yuechuan3, Zhou Xuewei1,2 & Ye Tao3

(1. State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation//Chengdu University of Technology, Cheng-du, Sichuan 610059, China; 2. Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, Sichuan 610059, China; 3. Tianjin Branch Company of CNOOC, Tianjin 300452, China)

NATUR. GAS IND. VOLUME 39, ISSUE 1, pp.33-44, 1/25/2019. (ISSN 1000-0976; In Chinese)

Abstract: The BZ19-6 deep buried-hill structural belt in the southwest of Bozhong Sag, Bohai Bay Basin, is a newly discovered super-giant oil and gas bearing area. The study on its reservoirs is still in the early stage, and the characteristics and control factors of reservoir development are not understood deeply. In this paper, cores, sidewall cores, rock sections were analyzed and described. Then, based on regional structural setting, mud logging and logging data, the buried-hill reservoirs in this area were analyzed from the aspects of petro-logical characteristics, reservoir space types and physical properties, the inherent factors influencing the development of the reservoirs were discussed, and distribution laws of the reservoirs were investigated. And the following research results were obtained. First, the deep buried-hill reservoirs of this belt are a pan-buried hill reservoir system composed of the Palaeocene–Eocene Kongdian Fm glutenite in the upper part and the Archean buried-hill metamorphic granite in the lower part. A multi-layer reservoir structure of glutenite pore zone, weathering crust dissolution fracture zone and inner fracture zone is formed. These reservoirs are complex in genesis and diverse in type. Second, the Archean buried-hill metamorphic granite reservoir can be vertically divided into weathering crust, inner fracture zone and tight zone, and it presents the dual characteristics of porous and fractured media. Third, the buried-hill weathering crust is mainly affected by strong dissolution and leaching superimposed with fracturing, forming fractured-porous reservoir space. The reservoir of inner fracture zone is mainly controlled by the superimposition of three-phrase fractures, which forms the main development period of buried-hill frac-tures since the Yanshanian. Fourth, the glutenite of Kongdian Fm is a typical sieve deposit and it is mainly controlled by the late dissolu-tion. Fifth, migmatization and supercritical fluid cryptoexplosion play a constructive role in the development of the reservoirs. In conclu-sion, the understanding of buried-hill glutenite and metamorphic reservoir system developed in this belt is conducive to determining the target and direction of next oil and gas exploration in this area.

Keywords: Bohai Bay Basin; Bohai Sea area; BZ19-6 deep buried-hill structural belt; Archean; Deep metamorphic granite reservoir; Pa-leogene; Glutenite reservoir; Dissolution; Structural fracture

基金项目：国家科技重大专项“渤海潜山成藏综合研究与有利勘探方向”（编号：2016ZX05024-003-010）、中海石油（中国）有限公司科研项目“渤海海域潜山石油地质特征、典型油气藏成藏机理与有利勘探区带预测”（编号：CCL2014TJXZSS0870）。

作者简介：侯明才，1968年生，教授，博士生导师，博士，本刊编委；主要从事大地构造沉积学、含油气盆地分析、层序岩相古地理学等领域的科研和教学工作。地址：（610059）四川省成都市成华区二仙桥东三路1号。ORCID：0000-0001-7583-9159。E-mail: houmc@ 通信作者：曹海洋，1988年生，博士；主要从事沉积学、层序地层学等方面的研究工作。地址：（610059）四川省成都市成华区二仙桥东三路1号。ORCID: 0000-0003-4618-4610。E-mail: chycdut@