珠江口盆地惠州凹陷转换体控沉-控储特性及其油气地质意义

Sedimentary-Reservoir Characteristics under Control of Transfer Model and Implications for Hydrocarbon Exploration in Huizhou Depression,Pearl River Mouth Basin

构造转换带以其重要石油地质意义而受到学者们的广泛关注,尤其强调转换斜坡对大型砂体展布方向及堆积范围的控制.针对转换带及附近陡坡带的砂体及优质储层分布规律的复杂性,以惠州凹陷西南缘为例提出一种基于"转换体"概念的转换体优质砂体预测方法.相比于转换带,转换体研究变"带"为"体",是对转换带的扩充和深入.研究范围上,将转换斜坡带与断控陡坡纳为组合体,强调两者在三维立体组合下沉积体存在动态时空交互作用;研究内容上,以"构造-地貌-沉积-储层"思路来分析优质砂体的成因及演化.基于"转换体"的优质砂体预测方法,指出惠州26洼西南缘可划分出"锐角-直角-钝角"三类转换体模型,在不同类型转换体的构造-地貌格局下,陡坡和转换斜坡扇体间具有孤立-叠加-联控三类控沉效应,其对应储层物性逐渐变好.系统解析惠州凹陷转换体控沉-控储特性对完善转换体系框架有理论意义,同时可服务大中型油气田的勘探需求.

Structural transfer zone has been widely concerned by scholars for its important petroleum geological significance,especially the control of the transfer slope on the distribution direction and accumulation range of large sand bodies.In view of the complexity of the distribution of sand bodies and high-quality reservoirs in the transfer zone and nearby steep slope zone,taking the southwest edge of Huizhou depression as an example,a prediction method of high-quality sand bodies in the transfer zone based on the concept of“transfer model”is proposed.Compared with the transfer zone,the study of transfer model is an extension and deepening of the transfer zone studies.In the research scope,the transfer slope zone and fault controlled steep slope are regarded as the combination,emphasizing that there is dynamic space-time interaction between the two sedimentary bodies under the threedimensional combination.In the research content,the genesis and evolution of high-quality sand bodies are analyzed with the idea of“structure-landform-sedimentation-reservoir”,so as to have stronger petroleum geological significance.Based on the concept of“transfer model”,in this paper it proposes that three types of transfer models of“acute angle-right angle-obtuse angle”can be divided in the southwest of Huizhou 26 sag.In the structure-geomorphic framework of different types of transfer models,there are three types of sedimentation control effects between the steep slope and the transfer slope fan,which are isolation-superimpositionjoint control,and their reservoir physical properties gradually become better.Systematic analysis of sedimentary-reservoir characteristics of transfer model in the Huizhou depression is of theoretical significance to improve the transformation system framework,and it can also meet the exploration demands of large and medium-sized oil and gas reservoirs.