CAJ | 학술논문

石油地球化学在油气勘探中的重要作用是为各种地质模型和勘探方案提供校正参数,进而提高勘探成功率.油气勘探项目最重要的关键环节之一是通过油源对比来确定盆地中最有效的源岩层位或源岩灶的位置.油源对比的可靠性很大程度上取决于所采用的地化参数是否既考虑了源岩的成因特征,又考虑了油气在输导层和储层中的质量转移和混合过程.本文探讨中国沉积盆地中四个悬而未决的地球化学问题.首先,通过对松辽盆地地质实例的解剖,笔者认为海侵在这个古代大型淡水湖泊中的优质油气源岩的形成过程中可能起过至关重要的作用.其次,通过对新华夏构造带包括渤海湾盆地未熟-低熟油的研究,笔者提出了数种未熟-低熟油的成因模式,进而认为真正的未熟源岩对已经发现的未熟-低熟油贡献甚微.再者,通过回顾相关的地质和地球化学证据,对吐哈盆地的油气主要来自煤源岩的认识提出了不同看法.最后,我们运用几项研究实例,来展示在象塔里木这样构造复杂的盆地中进行油气源对比必须考虑流体混源的问题.通过分析油源对比中常用的分子地球化学参数的基本假设和可能缺陷,我们提出一种质量分量法来探讨海相油-陆相油、煤成油-湖相油以及成熟油-未熟油等存在争议的问题.
석유지구화학재유기감탐중적중요작용시위각충지질모형화감탐방안제공교정삼수,진이제고감탐성공솔.유기감탐항목최중요적관건배절지일시통과유원대비래학정분지중최유효적원암층위혹원암조적위치.유원대비적가고성흔대정도상취결우소채용적지화삼수시부기고필료원암적성인특정,우고필료유기재수도층화저층중적질량전이화혼합과정.본문탐토중국침적분지중사개현이미결적지구화학문제.수선,통과대송료분지지질실례적해부,필자인위해침재저개고대대형담수호박중적우질유기원암적형성과정중가능기과지관중요적작용.기차,통과대신화하구조대포괄발해만분지미숙-저숙유적연구,필자제출료수충미숙-저숙유적성인모식,진이인위진정적미숙원암대이경발현적미숙-저숙유공헌심미.재자,통과회고상관적지질화지구화학증거,대토합분지적유기주요래자매원암적인식제출료불동간법.최후,아문운용궤항연구실례,래전시재상탑리목저양구조복잡적분지중진행유기원대비필수고필류체혼원적문제.통과분석유원대비중상용적분자지구화학삼수적기본가설화가능결함,아문제출일충질량분량법래탐토해상유-륙상유、매성유-호상유이급성숙유-미숙유등존재쟁의적문제.
Petroleum geochemistry contributes to exploration successes by providing key constraints for geological models and critical input to exploration scenarios. One of the most important tasks in a typical exploration program is to identify the most effective source intervals or kitchens in a basin, through oil-source correlation. The results of correlation are valid only if the geochemical parameters used address adequately the genetic characteristics of the source rocks as well as the mass transport and mixing processes of hydrocarbon fluids occurring in the carrier beds and reservoirs. This manuscript discusses four of the major contentious petroleum geochemical issues in China's sedimentary basins. It is suggested that marine incursions played a significant role in the formation of prolific petroleum source rocks in the gigantic, dominantly freshwater, Songliao Basin. Several models are proposed to account for the occurrence of immature oils in the Cathaysian rift system including the Bohai Bay Basin, thus immature source rocks are considered a mere minor contributor to the known economic immature oil resources. Both geological and geochemical evidence are reviewed to refute a dominantly coaly source for the petroleum discovered in the Turpan Basin. Results of case studies are presented to demonstrate the importance of recognizing petroleum fluid mixing to solve the oil-source correlation issues in the structurally complex Tarim Basin. In addressing the fundamental assumptions and potential flaws of the molecular geochemical parameters commonly used for oil-source correlation, the need of a mass fraction approach is proposed to deal with such contentious issues as marine versus lacustrine, coal versus lacustrine, and mature versus immature oils.