扇三角洲沉积储层地质知识库的建立及应用——以北部湾盆地涠西南凹陷流沙港组为例

Establishment and application of fan delta sedimentary reservoir geological database: a case study of the Liushagang Formation in Southwest Weizhou Depression,Beibu Gulf Basin

曾晓华 周伟 肖大志 袁凌荣 张晓禹 朱金起

中海石油（中国）有限公司湛江分公司，广东 湛江 524057

Zhanjiang Branch of CNOOC Ltd., Zhanjiang 524057, China

以北部湾盆地涠西南凹陷流沙港组为例，利用密井网资料，结合现代沉积考察，建立了扇三角洲沉积储层定量地质知识库。通过分析研究，将研究区流沙港组扇三角洲前缘沉积细分为5种微相类型，这些微相砂体有6种叠置模式。对现代扇三角洲沉积考察的定量数据采集统计分析结果显示，辫流坝长宽比为1.65～4.25，辫流坝与辫状水道宽度比为0.65～5.00，该数据为刻画实际地下地质体的展布提供了重要依据。扇三角洲地质知识库显示，辫状水道宽厚比为150～200，辫流坝宽厚比为170～220，分支水道宽厚比为180～230，河口坝宽厚比为400～545。依据地质知识库数据，研究区注水井部署方案将注采井距定在420～800 m，现场实施该方案后注水效果好。

Taking the Liushagang Formation in Southwest Weizhou Depression, Beibu Gulf Basin as an example, the quantitative geological knowledge database of fan delta sedimentary reservoir is established by combining modern sedimentary investigation and data of dense well pattern. The fan delta front sediments of Liushagang Formation in the study area are divided into five microfacies types. It is concluded that there are six superposition models of sandbodies. The results of quantitative data collection and statistical analysis of modern fan delta show that the length-width ratio of the braided flow dam is between 1.65 and 4.25, the width ratio of the dam to braided channel is between 0.65 and 5.00. The data provided an important basis for describing the actual distribution of underground geologic bodies. The geological knowledge database of fan delta shows that the width to thickness ratio of braided channel is between 150 and 200, that of braided flow dam is between 170 and 220, that of branch channel is between 180 and 230, and that of estuary dams is between 400 and 545. Based on the geological knowledge database, the injection-production well spacing is set between 420 m and 800 m in the water injection well deployment scheme，which has the good effect of water injection.

10.6056/dkyqt202103012