油气运聚定量模拟技术现状、问题及设想

Status,problems and proposals of the quantitative modeling techniques for hydrocarbon migration and accumulation

对于定量模拟技术的研发及应用,首先简要讨论初次运移(排烃),然后主要重点放在二次运移(烃类运移聚集)。关于初次运移,建议采用简单但争议少的方法计算排烃,其正确性由二次运移的模拟结果是否接近勘探实际来判别。关于二次运移,目前有4种运聚定量模拟技术:多相达西流法、流径法、混合法(多相达西流法+流径法)和侵入逾渗法。然而,这4个技术近10年来虽然各自有了较大的改进,但在克服各自的最大缺点问题上基本上没有突破:①多相达西流法虽有完整的时间模拟功能,但因受计算机资源所限而实用价值较差;②流径法和侵入逾渗法基本上没有时间模拟功能,即模拟对象通常仅是现今(0 Ma)的地质体,而能在关键时间(≠0 Ma)进行模拟尚在探索中;③由于混合法的实用价值主要来源于流径法,故严格来说混合法也基本上没有时间模拟功能。对于每一技术,概要介绍其技术背景、技术方法和应用效果;通过对比,指出各自的优缺点和适用条件,为未来研发提出改进方案。通过上述分析研究,提出了一个具有时间模拟功能的运聚定量模拟技术方案:在全时空的三维网格上,采用单相(水)达西流法技术计算超压,在数据稀少时采用流径法,在数据密集时采用侵入逾渗法。

Abstract：After a brief discussion of the development and application of quantitative modeling techniques for primary migration （hydrocarbon expulsion） , and this paper focuses on the study of modeling techniques in se- condary migration （hydrocarbon migration-accumulation）. For primary migration, it is proposed to adopt simpli- fied but less-debated methods for hydrocarbon expulsion calculation and verify their validity through comparing modeling results of secondary migration with real exploration data. As for secondary migration, at present there are four quantitative modeling techniques available： multi-phase Darcy flow, flewpath, hybrid method （multi- phase Darcy flow ＋ towpath）, and invasion percolation. Though great improvements have been made in these four techniques in the past 10 years, their particular disadvantages have not been by and large overcome. Their disadvantages include （ 1 ） though the multi-phase Darcy flow has excellent ability to model various times, it can- not generally be effectively applied due to limited computer resources; （2） both towpath and invasion percola- tion are basically unable to model different geologic times, i. e. , usually the modeled object is only the present- day （0 Ma） geologic body,while the modeling of other geologic times （ #0 Ma） is still under research; （3） since the practical value of the hybrid method results mostly from the towpath method, strictly speaking the hy- brid method also basically has no ability to model different geologic times. Herein summarizes the background, method and application of each technique, expounds the advantages, disadvantages, and applicability of each method, and proposes a plan for their future modification and development. The paper recommends a comprehensive scheme utilizing quantitative modeling techniques with the ability to model various geologic times. It uses single-phase （water） Darcy flow for calculating overpressure in full space-time. The flowpath modeling is adopted when the data is sparse and invasion percolation is employed when the data is dense.