摘要
南堡凹陷下第三系火山岩及与火山活动相关的碎屑岩围岩储层单井产量高、稳产能力强,具有良好的勘探开发潜力,但该类储层纵向上与火山岩多呈现上覆直接接触关系特征,厚度具有不均匀性,横向变化大.受地震资料分辨率及火山岩强反射等影响,储层预测困难,制约了该领域下步勘探开发部署.本文以南堡凹陷2号构造研究为例,首先通过测井岩石物理分析和叠前地震资料的对比分析发现,纵波阻抗是识别火山岩与围岩储层的敏感参数,入射角CRP道集近角优势叠加地震能够提升火山岩反演分辨率,基于此,第一步运用迭代低频模型确定性反演技术实现规模性火山岩单体概率预测,第二步将火山岩单体三维岩性概率作为先验信息进行相控地质统计学反演,实现火山岩与沉积岩地震反射信号分离,有效消除火山岩强反射对围岩储层预测的影响,提高了围岩薄储层预测精度;预测效果显示,本次研究建立的迭代低频确定性反演和相控地质统计学反演两步法串联工作流程兼具预测性与描述性,能够解决多期火山岩与储层互层沉积模式下隐蔽性油藏岩性识别问题,在类似资料及地质条件研究区具有借鉴应用价值.
The volcanic rock and surrounding clastic rock reservoir related to volcanic activity in the middle and deep formation of Nanpu Sag has the feature of high single well production and strong stable production capacity,which proving that this kind of reservoir has good exploration and development potentiality,but most of these reservoirs overlay on volcanic rocks directly in vertical,and its thickness varies rapidly on lateral. Because of the limited resolution of seismic data and the affection of strong volcanic rocks’ reflection,resulting in difficulties in reservoir predication. It restricts the following exploration and development activity in this oilfield. This paper is a case study in No. 2 structure of Nanpu sag. First,based on the comparative analysis of log rock physics and pre-stack seismic data,it is found that P-wave impedance is a sensitive parameter to identify volcanic rock with surrounding reservoir. The near angle CRP gather stack seismic can improve the inversion resolution of volcanic rocks. Firstly,we use iterative low-frequency model deterministic inversion to predict the probability of single basalt geobodies. Secondly,taking the three-dimensional lithology probability of volcanic rock as a priori information for facies controlled geostatistical inversion,Separatine the seismic reflection signals from volcanic and sedimentary rocks,and eliminating the influence of strong reflection of volcanic rocks on surrounding rock reservoir prediction effectively. This improves the accuracy of thin surrounding rock’s prediction. The inversion results show that the two-step series workflow of iterative low-frequency deterministic inversion and facies-controlled geostatistics inversion established in this study is both predictive and descriptive. It has the capability of solving the problem of lithology identification of subtle reservoir under the multi-stage volcanic rock reservoir interbedding sedimentary model. The workflow of this case study has extendable and utility value to similar data and geol
作者
杨晓利
王方鲁
张明
YANG XiaoLi;WANG FangLu;ZHANG Ming(Exploration and Development Institute of Jidong Oilfield,Tangshan 063004,China)
出处
《地球物理学进展》
CSCD
北大核心
2022年第4期1640-1649,共10页
Progress in Geophysics
关键词
岩石物理
近角叠加
相控反演
火山岩
围岩储层
Rock physics
Near offset stack
Facies-controlled inversion
Volcanic rock
Surrounding reservoir
