西湖凹陷HY气田低渗储层分类描述及流体检测  

CATEGORY DESCRIPTION AND FLUID DETECTION FOR LOW PERMEABILITY RESERVOIRS IN HY GAS FIELD OF XIHU SAG

作　　者：李文俊 段冬平 何贤科 陈波 王伟 LI Wenjun;DUAN Dongping;HE Xianke;CHEN Bo;WANG Wei(Shanghai Branch of CNOOC Ltd.,Shanghai 200335,China)

机构地区：[1]中海石油(中国)有限公司上海分公司,上海200335

出　　处：《海洋地质前沿》2021年第12期17-26,共10页Marine Geology Frontiers

基　　金：国家自然科学基金“东海深层低渗-致密气储层体系质量差异性成因机制及演化模式”(U19B2006);中海石油(中国)有限公司科技项目“西湖凹陷中深层河流相储层表征及剩余油气挖潜研究”(YXKY-2019-SH-01)。

摘　　要：HY气田位于西湖凹陷中央反转构造带南部,主要目的层花港组上段为浅水三角洲沉积,储层为中低孔低渗储层,地震响应特征表现为Ⅱ类AVO(Amplitude Variation with Offset)。受压实作用影响,储层孔隙度由上至下逐渐降低,AVO类型由Ⅱb类向Ⅱa类转变。从岩石物理分析、正演模拟、相位转换及AVO投影角度旋转等方面,制定了针对低渗储层不同AVO特征的精细描述方法。研究认为,区内中孔低渗储层表现为Ⅱb类AVO响应特征,叠后地震砂顶标定于波谷,储层描述应采用叠后-90°相移波形解释、叠后包络属性流体检测等方法;低孔低渗储层表现为Ⅱa类AVO响应特征,储层描述应采用叠后0°相移波形解释、叠前扩展弹性阻抗流体检测等方法。基于上述"一层一策"储层精细描述方法,成功指导研究区多口钻井实施,储层预测及流体检测成功率100%,大幅改善气田开发现状。The HY Gas Field is located in the south of the central inversed structural belt of the Xihu Sag. The upper part of Huagang Formation is dominated by shallow water deltaic deposits, and the reservoir is characterized by medium-low porosity and low permeability, of which the seismic response characteristics are of class II AVO.Affected by compaction, the reservoir porosity gradually decreases from top to bottom, as AVO type changes from Class IIb to Class IIa. In this paper, a detailed description method for the low permeability reservoir with different AVO characteristics is proposed from petrophysical analysis, forward simulation, phase conversion and AVO projection angle rotation. It is considered that the medium-porosity and low-permeability reservoirs in the area are characterized by class IIb AVO response characteristics, and the post-stack seismic sand top is calibrated in the trough. Reservoir description should adopt post-stack 90 degree phase shift waveform interpretation, poststack envelope attribute fluid detection, etc. Low porosity and low permeability reservoirs are characterized by class IIa AVO response characteristics. Reservoir description should use post-stack 0 degree phase shift waveform interpretation, pre-stack extended elastic impedance fluid detection and other methods. Based on the fine reservoir description method of "one method for one layer", multiple wells were successfully drilled in the study area, and the success rate of reservoir prediction and fluid detection was 100%, which has greatly improved the development of the gas field.

关 键 词：西湖凹陷 低渗储层 AVO特征 地震波形解释 扩展弹性阻抗 

分 类 号：P744.4[天文地球—海洋科学] P618.13