四川盆地东北部龙会场区块长兴组生物礁储层特征及主控因素  

Bioreef reservoirs of Changxing Formation,Longhuichang area,northeastern Sichuan Basin:Characteristics and main control factors

作　　者：王蓓 任洪明[2] 朱占美 雷小华[2] 胡碟 杜磊[2] Wang Bei;Ren Hongming;Zhu Zhanmei;Lei Xiaohua;Hu Die;Du Lei(Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Northeastern Sichuan Gas District,PetroChina Southwest Oil&Gasfield Company,Dazhou,Sichuan 635000,China)

机构地区：[1]中国石油西南油气田公司勘探开发研究院,四川省成都市610041 [2]中国石油西南油气田公司川东北气矿

出　　处：《天然气勘探与开发》2021年第3期19-29,共11页Natural Gas Exploration and Development

摘　　要：龙会场区块上二叠统长兴组生物礁气藏是四川盆地东北部复杂气藏的典型代表,该气藏具有储层非均质性强、“一礁一藏”等特点。基于二维地震等资料的储层表征存在不准确性,制约了气藏的科学、高效开发。利用岩心照片、铸体薄片、测井解释成果、三维地震等资料,在研究储层特征基础上,依据压汞试验划分储层类型,利用三维地震刻画早、晚两期生物礁储层展布规律,进而剖析储层发育主控因素。研究结果表明:①龙会场长兴组生物礁气藏非均质性较强,主要储集岩以残余颗粒云岩或具颗粒幻影的细—中晶云岩为主,粒间(内)溶孔、晶间(溶)孔及生物溶模孔为主要储集空间,储层具低孔、低渗特征;②明确了研究区储层类型主要以III类储层,即裂缝—孔隙型储层为主,明确了早、晚两期生物礁地震响应模式;③研究区早期生物礁储层沿台缘带靠台内发育,晚期生物礁储层沿台缘主体呈带状分布,早、晚两期礁储层呈“错位叠置”的关系;④沉积环境控制储层的空间展布,成岩作用控制优质储层分布,构造作用及裂缝提高储层的渗流能力。In Longhuichang area, Sichuan Basin, the bioreef gas reservoirs of Changxing Formation are regarded as representatives of complex ones in northeastern basin. They are characterized by strong heterogeneity and "one bioreef and one reservoir". And the characterization based on 2D seismic data is uncertain, which may restrict the scientific and efficient development of the gas reservoirs. So, using core photographs, results from cast thin-section identification and well-logging interpretation, and 3D seismic data, on the basis of reservoir characteristics, the reservoir types were divided by means of mercury intrusion experiment. And the distribution laws of both early and late bioreef reservoirs were described by 3D seismic data. Furthermore, the main factors controlling reservoir development were analyzed. Results show that:(1) the Changxing bioreef gas reservoirs in this area are characterized by strong heterogeneity, and low porosity and permeability. The main reservoir rocks are composed of residual granular dolomite or fine-medium crystalline dolomite with granular phantom, and the reservoir space is dominated by intergranular(intragranular) dissolution pore, intercrystalline(dissolution) pore, and bio-moldic pore;(2) the main reservoirs belong to type Ⅲ(fractured-porous ones), and the seismic response models of both early and late bioreef are confirmed;(3) the early bioreef reservoirs are developed along platform margin zone or near platform inside, whereas the late ones representing belt-like distribution along the main body of platform margin. And the early bioreef reservoirs are in relation of "dislocation and superimposition" to late ones;and(4) sedimentary environment may control the spatial distribution of reservoirs, diagenesis may affect the distribution of quality reservoirs, and tectonism and fractures improve their seepage ability.

关 键 词：四川盆地 长兴组 生物礁 储层特征 地震响应特征 储层主控因素 

分 类 号：P618.13[天文地球—矿床学]