油气藏开发过程中井间砂体对比与连通关系类型探讨

The Correlation & the Connectivity Types of Sandbody In the Process of Oilfield Geological Study

油田开发研究中,一般通过"旋回对比、分级控制、不同相带区别对待"的单油层对比方法确定井间砂体的连通关系。据沉积微相、砂体成因关系,叙述了不同情况下多井对比与砂体连通关系确定方法:①河流相单砂层分布特点是横向变化快,砂层厚度存在多微相类型,形成多种砂体连通关系。砂体连通关系的确定有多期河流砂体叠置型、砂体相变型、孤立水道下切砂体型3种主要对比模式;②湖相三角洲井间单砂层对比关键是模式的建立及等时面与等岩性面的确定。由于湖相三角洲砂层发育程度、规模不如海相三角洲,所以等时面与等岩性面确定与海相标准三角洲的确定存在一定差异。油田开发过程中,有了正确的井间砂体对比关系,就能准确确定单井钻遇油砂体情况及油层连通率,为合理部署井网密度,提高采收率提供地质依据。

In the process of oilfield development geological study, the correlation relationship and connectivity of the sandbody could be scertained by single oil layer correlation method, that based on＂cycle correlation, step control and ＂distinctive treatment for different facies belt＂ Because of great changes on the continuity and thickness stability of sandbody, it is difficult to show true features of sandbody by simple methods.It is according to make different correlation model by changes of sedimentary microfacies.The paper describes for methods of multi-inter-well correlation and sandbody connectivity on the basis of sedimentary microfacies and sandbody genesis relationship.（1）The distribution of the single fluvial sandbody is characterized by lateral changes quickly, especially thickness of sandbody, and presence of multi-microfacies pattern,thereby forming a variety of connected relationship of sand body. There are three main correlation patterns for connected relationship that include are concerned by which are stacking pattern of multi- periods fluvial sandbody, sandbody facies-change and single incised channel body.（2）It is complex type.for the connected relationship of delta front facies sandbody.It is the key of correlation for delta to correctly determine the relationship of isochronous surface and iso-lithology surface,and It can be considered as the correlation method of isochronous surface and iso-lithology surface for the delta sedimentary facies.Oil layer connectivity and injection-production relationship,single side up horizontal sandstone layer connectivity, depends largely on well spacing density and single sand body.Which drilled the single sandbody.