TSM盆地模拟资源分级评价技术及其在苏北溱潼凹陷中的应用

【作者】 徐旭辉；

【导师】 周祖翼；

【作者基本信息】 同济大学 ， 海洋地质学， 2004， 博士

【摘要】 TSM盆地模拟资源评价系统是以朱夏院士3T（环境）-4S（作用）-4M（响应）盆地研究系统思想为指导，从盆地原型到圈闭的系统网络按埋藏、热、生烃和运聚等四罗软件运行系统综合的数值模拟。构造-热体制的变化，为盆地提供了原型控制油气P（压力）、V（体积）、T（温度）动态变化的边界条件，使得系统合理地进行生烃量、排烃量直至圈闭资源量的计算。通过理论建模—实例校验—盆地模拟的工作程序，初步建立了盆地动态成藏系统网络整合的方法；通过在苏北盆地溱潼凹陷的具体应用研究，取得了一系列成果。一、TSM盆地模拟是一个适用的资源分级评价系统1、研究建立了以活动论构造历史观和盆地原型及其并列迭加为特色的油气盆地资源分级评价理论方法体系。强调从盆地整体出发进行盆地油气资源的分级评价，就是说无论在勘探工作的哪个阶段，都应该从盆地整体到局部进行分析评价，都有盆地、区带和圈闭的资源评价问题；其次，以活动论构造历史观为指导，强调应根据具体的地质情况，以盆地分析为前导，对所评价的地区进行盆地原型及其并列迭加分析，据此进行不同级别的油气资源评价；第三，各个级别的资源评价都应当考虑从油气盆地地质作用以及响应的各个方面因素，反映系统整合的效应，同时各有所侧重。在研究过程中，深入剖析具有较高勘探程度的苏北溱潼凹陷，通过综合地质作用和油气响应等各方面因素，得到各个区带的模拟资源量及其演化情况，得到了不同假设条件下的比较，得到重点局部构造的油气资源评价分析，其结果可以为油气资源的分级评价起重要的作用，在现有的资料基础上提供下一步勘探部署的建议。该方法的成功实施已充分显示出其作为一个盆地分析和油气资源评价的有力工具，其“思考”的系统性、定量性和动态的演化观念是人工无法比拟的，并随着勘探程度不断提高，模型方法的不断更新，模拟可以实现“评价与再评价”。2、初步建立了以埋藏史、热史、生烃史和运聚史等四史为核心的原型地质作用与油气响应关系的系统整合模拟—TSM盆地模拟资源分级评价技术。该系统强调了地质概念模型研究和不同构造-热体制下原型盆地的并列迭加关系分析是模拟实施的重要前提。方法具有检验地质概念模型、揭示盆地演化过程的功能，最终以预测油气资源的数量和分布为目的，并随着勘探进程进行滚动评价，达到指导勘查的目的。从效果、用途等方面看有以下特点：在模型系统方面：①正确的盆地研究理论指导，强调了地质调查是模拟运行的前提。②明确反映了不同构造-热体制与油气系统演化之间作用-响应的确定性关系。③摸拟结果系统、动念、定量，提供了合理预测油气的依据。在软件系统方面：①系统模块化，从设计至编程均为自主开发，拥有自主的核心技术。②软件系统适应中国复杂结构盆地的情况，可视不同地质情况“并列”或“迭加”的调整模块系统；从而可以通过单项模拟的“组装”实现盆地大系统的、动态的综合。③系统处于发展之中，模型库的不断扩充，使得方法系统不断完善，系统具有很强的扩展能力。④不断跟踪国内外发展，模块具有先进性，可与国际先进水平相比。⑤软件系统涵盖了从埋藏史、热史、生烃史和运聚史等油气地质研究的各项内容，是一个综合的、互动的系统。⑥通过在各种不同勘探程度盆地的实际应用，取得良好的效果；可直接服务于油气评价，是一个有较强实用性的资源评价系统。针对苏北溱潼凹陷典型实例，建立了断陷、拗陷和剥蚀、物质充填和热传导等地质作用模型，建立了热降解生烃、临界饱和度排烃以及运移路径等一系列油气响应模拟模型；实现了二维的模拟，建立了较为成熟的断-拗原型迭加油气评价系统。勘探应用表明，TSM系统是一套能够揭示盆地演化史和进行油气选区评价及远景区带定量评价的分析和模拟方法；是一套高效、可信且低成本的盆地资源评价方法，可能是一个减小勘探风险的重要工具。在勘探评价初期，使用有限的地质资料，TSM系统可以用于油气资源潜力分析和选区评价；当有更多资料时，TSM系统可以定量评价有利区带的油气远景储量；从而在不同勘探阶段实现了对不同级别资源的综合评价。二、在溱潼凹陷的评价中所取得的新进展通过对苏北溱潼凹陷的应用，根据不同勘探程度，相应进行了盆地、区带和圈闭油气资源的评价，从而对油气盆地资源分级评价理论和系列技术进行了实用检验。应用表明，针对不同勘探程度和评价目标，油气盆地分级评价技术均能检验地质概念模型的正确性、揭示油气成藏的动态过程、进行合理的资源分级评价，从而提供勘探决策，降低勘探风险。论文取得主要进展有：（1）系统、定量、动态地描述和分析了溱潼凹陷晚白垩世-古新世断陷、渐-始新世断陷和晚第三纪-第四纪拗陷的发育及迭加改造过程。计算了吴堡及三垛运动的不整合面的剥蚀量，恢复了沉积间断过程。分析反映两期断陷有其不同风格，首先，两期断陷的受力方向不同，沉降中心亦有所偏差，古新世时期沉降、沉积的重点在淤溪、戴南镇等中西部一线。渐—始新世断陷期凹陷的沉降、沉积受北东向断裂控制，其沉降重点在主断裂附近，以溱潼镇、时堰、大凡庄等中东部一线为最。其次，晚白垩世-古新世断陷期拉张量和沉降幅度都大于渐-始新世断陷期。凹陷除了南北方向可以划分断阶带、深凹带和斜坡带之外，在东西向上也具有不同的构造发展特征。（2）计算表明，溱潼凹陷主要烃源岩为泰州组及阜二段，排烃高峰期为23.2Ma，其次为阜三、阜四段。戴南组基本无烃排出。凹陷的总生烃量为12.4271×10⁸t，排烃量为6.2260×10⁸t。从平面分布上看，泰州组的烃源岩在溱潼次凹和港口—俞垛次凹生、排烃能力最强，时埝次凹次之，内斜坡亦有一定生烃能力，阜二段烃源岩在港口、俞垛、溱潼、时埝次凹生、排烃量最大，而阜四段烃源岩生、排烃量最大在溱潼、戴南、时埝一线，港口、俞垛一线次之。（3）依据深凹部位烃源岩排烃势能最大脊线和构造面貌，共将凹陷划分为南部断阶带、内斜坡带、枢纽带和外斜坡带等4个区带，11个区块。从运聚计算分析，内斜坡带、断阶带是油气运聚的最有利地区。资源量主要集中在泰州组、阜一段、阜三段和戴南组，而阜三段（E_f³）是凹陷油气资源最富集的层位，资源量约248×10⁶t，约占凹陷资源量的40％以上。结合目前勘探成果分析，内斜坡带（下溪、港口、叶甸、边城、戴南等区块）的阜宁组是下一步勘探的重点目的层位；对于中构造层而言戴南组(E_?)应以内斜坡带为主要目的工区，三垛组（E_s）应以断阶带为主要目的工区。（4）在区带资源量定量评价的基础上，根据主要控油断层的发育与分布、构造圈闭的发育状况等进行分析，动态地再现了油气在储层中的聚集。并且典型模拟评价了斜坡带上的帅垛、顾庄、朱家圩、下溪等四个局部构造，尝试性地计算了帅垛构造阜三段油气运聚量为0.608×10⁶t，顾庄构造阜三段油气运聚量为0.345×10⁶t；从而对各区带、各局部圈闭的油气资源量进行了定量预测。更多还原

【Abstract】 TSM basin modeling for resource evaluation system is directed by the thoughts of basin research of 3T (environments) - 4S (actions) - 4M (responses) proposed by Academician Zhu Xia. which is simulated in a synthetic software composed of burial. thermal, hvdrocarbon generation and migration history. The modeling targets are from basinal prototypes to traps. The ’should be so’ changes of tectonic - thermal system provided dynamic boundary conditions for the changes of pressure (P), volume (V) and temperature (T) controlling hydrocarbon in a protobasin, which make it is possible to reasonably, calculate amounts of hydrocarbon generation, migration and even the resource of a trap. Through theoretical model, practical adjustment and basin modeling, a dynamic modeling system for hydrocarbon accumulation is constructed. Some good results are gained alter it is applied to the study, of Qingtong depression in northern. Jiangsu Basin.1. TSM basin modeling system is a suitable tool for hierarchy evaluation of petroleum resource1.1 Theoretical systemIt is emphasized that hierarchy evaluation of petroleum resource in a basin should take the basin as a whole, i.e. it should be analyzed and assessed from entirety to part of the basin at any stages of petroleum exploration. There are different assessment objects in a basin, zone or trap. Secondary, based on mobilism of tectonic history. basin prototype and its superimposition and juxtapositon should be analyzed, and different level of resource is evaluated in accordance with different geological conditions. Third, all factors of geological activity and its response in a basin should be considered in different levels of evaluation of petroleum resource, and the whole effect should be reflected with emphasis of some important aspects. Qingtong depression of the northern Jiangsu Basin with higher level of exploration is studied in detail. After integration of geological actions and their responses in the basin, the simulated resource of oil zones is indicated, the results are compared with various geological conditions, and petroleum resource in principle local structures is analyzed. The results may provide important foundation for hierarchy evaluation of hydrocarbon resource and can give out suggestion for future exploration without more data available. The method is a powerful tool for basin analysis and resource assessment. Its systemticness, quantitativeness and dynamicness are far beyond the hulnan’s ability. With the increasing level of exploration and the continuously improvement of modeling method, "assessment and re-assessment" of simulation can be reached.1.2 TSM basin modeling technique for hierarchy evaluation of petroleum resourceIt is emphasized that study of geoIogical concept model and analysis of basinal superimposition and juxtaposition under different tectonic and thermal system are the important basis for basin modeling. The geological concept model can be tested and the basin evolution process can be revealed by the method. And its purpose is to predict amount and distribution of petroleum resource. It may perform real time assessment with exploration progress and conduct the exploration. The characteristics of the modeling system in terms of its result and function is as followings: a) With correct theory of basin research, it is emphasized that geological study is the prerequisite for modeling operation, b) A definite ’action - response’ relationship between the different tectonic - thermal system and the evolution of petroleum svstem is indicated, c) Modeling results are systematic, dynamic and quantitative, and provide reasonable prediction of petroleum distribution. In terms of the software, there are following characters: a) It consisted of modules which are independent in design and development, and we own the core technique, b) The software is suitable for complex basin structure of China. The module may be adjusted according to different ’juxtaposition’ or ’superimposition’ of basinal prototypes, thus dynamically fulfill integration of modeling system, c) There is strong expanding ability of the system during expansion of module warehouse and development of method system, d) The software covers various aspects of petroleum geology such as burial, thermal, hydrocarbon generating and migrating histories. It is a integrated and mutual system. e) After practical application in basins with different levels of exploration, the rnethod may directly be applied to evaluation of petroleum resource and good results are achieved. Taking Qingtong depression of the northern Jiangsu Basin as an example. geological models of fault-depression, depression, erosion, sediment filling and thermal conduction are designed, a series of modeling models for hydrocarbon responses such as hydrocarbon generation, expulsion and migration pathway are constructed, so a relative well-considered petroleum evaluation system with prototype superimposition of fault depression and depression is developed. The exploration practice has showed that TSM system may reveal basin evolution history, carry out selected-area assessment, and quantitatively appraise prospective oil zone. It is a high effective, reliable and low cost evaluation system of basin resource, and it may be an important tool for reducing exploration risk. In the early stage of exploration, TSM system can be used to assess the potential hydrocarbon resource by limited geological data. As soon as more data is collected, the system may quantitatively predict prospective reserve for the favourable zone, Therefore, synthetic evaluation of petroleum resource in different stages of exploration is fulfilled.2. Advances in evaluation of Qingtong depressionOn basis of degree of exploration in Qingtong depression, petroleum resource in basinal, zonal and trap levels is carried out, so the hierarchy evaluation and serial techniques of petroleum resource are practically tested. The results showed that. for different exploration degree and different evaluating objects, the hierarchy evaluation technique of petroleum basin can test validity of geological concept model, reveal dynamic course of hydrocarbon accumulation, and reasonably assess resource in different levels. Thus. the decision-making can be improved and exploration risk may be lowered. Main advances of the study are as followings.a) The development, superimposition and modification of Late Cretaceous - Paleocene fault depression, Oligocene - Eocene fault depression and Neocene - Quaternary depression in Qingtong depression are described and analyzed systematically, quantitatively and dynamically. Erosion amount of unconformities formed during Wubao and Sanduo movements is calculated, and depositional hiatus is restored. It indicates that there are different styles for the two fault depressions. First. the two fault depressions have different stress directions, and the subsidence centers are little different. The subsidence and deposition center during Paleocene is in Yuxi and Dainan areas, the central west part of the depression. Subsidence and deposition are controlled by northeastern trend fault during Oligocene - Eocene, and subsidence is around the fault and Qingtong, Shiyan and Dafangzhuang areas, the central east part of the depression, are the center. Secondary, extension amount and subsidence range in Late Cretaceous - Paleocene fault depression period are larger than those in Oligocene - Eocene period. Step fault block, deep depression and slope can be divided along south - north direction in the depression, and there also are different structural characteristics in east - west direction.b) Calculation result showed that main source rocks are Taizhou formation and member Fu-2 with hydrocarbon expulsion peak at 23.2 Ma. Member Fu-3 and Fu-4 may be the minor source rocks. No hydrocarbon is expulsed from Dainan formation. Total amount of hydrocarbon generated in the depression is 12.4271*10~8t, and expulsed hydrocarbon is 6.2260*10~8t. In plane, hydrocarbon generation and expulsion of source rocks of Taizhou formation are the strongest in Qingtong, Gangkou - Yuduo sags. Shinian sag is placed the second, and inner slope has some ability of hydrocarbon generation. And those of member Fu-2 are concentrated in Gangkou. Yuduo, Qingtong and Shinian sags. For source rocks of member Fu-4, hydrocarbon generation and expulsion are mainly in Qingtong, Dainan and Shinian areas, with minor in Gangkou and Yudou areas.c) According to the largest crest line of hydrocarbon expulsion potential of source rocks and structural pattern in the deep part of the depression, the depression can be divided into 4 zones called southern step fault block, inner slope, hinge belt and outer slope, which can further be divided into 11 blocks. On basis of calculation of hydrocarbon migration and accumulation, inner slope and step fault block are the most favourable location for hydrocarbon accumulation. Reserve is mainly concentrated in Taizhou formation, member Fu-1 and Fu-2 and Dainan formation, and member Fu-3 (Ef~3) is the richest reservoir with reserve of about 248*10~6t that owns 40% of the total reserve in the depression. In accordance with present result of exploration, Funing formation in the inner slope (Xiaxi, Gangkou, Yedian, Biancheng and Dainan areas) is the future target for exploration. In terms of the middle structural horizon, Dainan formation (Ed) is the target in inner slope and Sanduo fonnation (Es) is the target in step fault block.d) On basis of quantitative evaluation of zonal resource amount, combining with analysis of development and distribution of main controlling faults and structural traps. hydrocarbon accumulation in the reservoirs is dynamically reproduced. Four local structures named Shuaiduo, Guzhuang, Zhujiawei and Xiaxi are simulated and assessed. The calculated accumulation amount of member Fu-3 in Shuaiduo structure is 0.608*10~6t, and in Guzhuang structure is 0.345*10~6t. Thus, hydrocarbon resource in every block and every local trap is predicted quantitatively.更多还原