Simulation experiment on hydrocarbon generating potential of various source rocks on the northern margin of the Qaidam Basin,Qinghai, China     

Xin Li  Dongliang Wang  Baoquan Liu  Chunling Ren  Jianying Guo  Xuefeng Su  Jian Wang 《中国地球化学学报》2008,27(4):412-419

The northern margin of the Qaidam Basin is one of the main oil-gas exploration areas in western China, where source rocks are composed mostly of Middle and Lower Jurassic dark mud shale, carbargillite and coal. A large number of subsurface and outcrop samples differing in lithology with different types of organic matter were selected for resource evaluation, research and calculation. And among them, 13 samples were used for simulation experiment on hydrocarbon generating potential of various source rocks. At first, two kinds of heating modes were compared through simulation experiment, including single temperature-step heating and continual heating. Perhaps, the process of hydrocarbon generation and expulsion occurred naturally between a close system and an open system. In addition, the first heating mode was convenient, and all its reaction products were involved in the whole thermal evolution, and the final simulation experimental results were basically in consistency with the natural evolution trend Therefore, the first heating mode was adopted and the hydrocarbon yield of every sample was worked out. According to the type and lithology of organic matter and the hydrocarbon yield of samples for simulation experiment, hydrocarbon generation and expulsion mode with three kinds of lithology and five types of source rock has been established to provide the basis for hydrocarbon generation evaluation, research and resource calculation.  相似文献   

Formation Dynamics and Quantitative Prediction of Hydrocarbons of the Superpressure System in the Dongying Sag   总被引：1，自引：0，他引：1  

SUI Fenggui  HAO Xuefeng  LIU Qing  ZHUO Qin’gong  ZHANG Shouchun 《《地质学报》英文版》2008,82(1):164-173

Based on the theory of formation dynamics of oil/gas pools, the Dongying sag can be divided into three dynamic systems regarding the accumulation of oil and gas： the superpressure closed system, the semi-closed system and the normal pressure open system. Based on the analysis of genesis of superpressure in the superpressure closed system and the rule of hydrocarbon expulsion, it is found that hydrocarbon generation is related to superpressure, which is the main driving factor of hydrocarbon migration. Micro fractures formed by superpressure are the main channels for hydrocarbon migration. There are three dynamic patterns for hydrocarbon expulsion： free water drainage, hydrocarbon accumulation and drainage through micro fissures. In the superpressure closed system, the oil-driving-water process and oil/gas accumulation were completed in lithologic traps by way of such two dynamic patterns as episodic evolution of superpressure systems and episodic pressure release of faults. The oil-bearing capacity of lithologic traps is intimately related to reservoir-forming dynamic force. Quantitative evaluation of dynamic conditions for pool formation can effectively predict the oil-bearing capability of traps.  相似文献   

Hydrous pyrolysis of a Type III source: fractionation effects during primary migration in natural and artificially matured samples     

C.S. Mishra  U. Samanta  A. Gupta  N.J. Thomas  K.N. Misra 《Organic Geochemistry》1996,25(8):489-505

A core from the Cambay Shale Formation of the Cambay Basin, containing immature Type III organic matter, was pyrolysed at 300°C for different durations of time to different maturation levels. Fractionation effects were studied employing a three-step extraction technique after removal of the expelled pyrolysate. The extractable organic matter (EOM) obtained on extraction of the whole core is assumed to be that present in open pores, while that obtained on finely crushing the sample is assumed to be that present in closed pores. The EOM obtained from 1 cm chips is termed EOM from semi-open pores. The gross composition of the pyrolysates expelled during pyrolysis is not similar to the oils reservoired in the area, and there is no significant fractionation observed between expelled pyrolysates and unexpelled EOM. Our study indicates movement of fluids between closed, semi-open and open pores. In both systems, there is a higher concentration of EOM in open pores than in semi-open and closed pores, and the fraction of EOM in open pores is much greater in the artificial system than in the natural system. Fractionation effects on n-alkane and isoprenoid hydrocarbon-based parameters were also studied. n-Alkenes are present in semi-open and closed pores of the immature core and in the core after it was pyrolysed to 300°C for 6 and 48 h, but are absent in the open pores. n-Alkenes are present in closed pores in the naturally matured core. Presence of n-alkenes in the pyrolysates expelled during the 6 and 48 h experiments, but their absence in the open pores of the core, indicates that expulsion also occurs through temporary microfractures during laboratory pyrolysis, whereas in the natural system expulsion from closed pores seems to be only via semi-open and open pores.  相似文献   

孔隙流体压力与流体排驱的关系   总被引：2，自引：3，他引：2  

冯乔  张小莉 《地质论评》1997,43(3):297-302

本文讨论了在压实作用下孔隙流体压力的形成以及与流体排驱的关系，指出异常孔隙流体压力是因岩石渗透率变化引起毛细管力增加而产生的，且二者之间在流体压力孕育过程中一直维持一个动态平衡状态。对于连续沉积的盆地，只有当异常孔隙流体压力增加到超过岩石的抗剪强度时，因岩石发生剪切破裂导致毛细管力降低，流体才被排出；对于强烈构造变动的盆地，因地层大量剥蚀引起负荷压力降低，其降低幅度达到或超过岩石的抗张强度时，岩石  相似文献   

Gas generation and expulsion characteristics of Middle–Upper Triassic source rocks,eastern Kuqa Depression,Tarim Basin,China: implications for shale gas resource potential     

P. Wang  X. Chen  J. Li  H. Yang  F. Jiang 《Australian Journal of Earth Sciences》2013,60(7):1001-1013

Frontier exploration in the Kuqa Depression, western China, has identified the continuous tight-sand gas accumulation in the Lower Cretaceous and Lower Jurassic as a major unconventional gas pool. However, assessment of the shale gas resource in the Kuqa Depression is new. The shale succession in the Middle–Upper Triassic comprises the Taliqike Formation (T₃t), the Huangshanjie Formation (T₃h) and the middle–upper Karamay Formation (T_2–3k), with an average accumulated thickness of 260 m. The high-quality shale is dominated by type III kerogen with high maturity and an average original total organic carbon (TOC) of about 2.68 wt%. An improved hydrocarbon generation and expulsion model was applied to this self-contained source–reservoir system to reveal the gas generation and expulsion (intensity, efficiency and volume) characteristics of Middle–Upper Triassic source rocks. The maximum volume of shale gas in the source rocks was obtained by determining the difference between generation and expulsion volumes. The results indicate that source rocks reached the hydrocarbon expulsion threshold of 1.1% VR and the hydrocarbon generation and expulsion reached their peak at 1.0% VR and 1.28% VR, with the maximum rate of 56 mg HC/0.1% TOC and 62.8 mg HC/0.1% TOC, respectively. The volumes of gas generation and expulsion from Middle–Upper Triassic source rocks were 12.02 × 10¹² m³ and 5.98 × 10¹² m³, respectively, with the residual volume of 6.04 × 10¹² m³, giving an average gas expulsion efficiency of 44.38% and retention efficiency of 55.62%. Based on the gas generation and expulsion characteristics, the predicted shale gas potential volume is 6.04 × 10¹² m³, indicating a significant shale gas resource in the Middle–Upper Triassic in the eastern Kuqa Depression.  相似文献   

应用荧光显微组分定量评价煤的生烃排烃潜力     

赵师庆  吴观茂 《煤田地质与勘探》1993,21(6):18-22

在研究镜质组类型基础上，把富氢镜质组（荧光镜质体）作为有折扣的富氢显微组分（类脂组）对待，提出了利用荧光显微组分丰度－ＦＭＴ参数作为评价不同还原类型煤生烃，排烃的定量指标。煤岩学标志，有机地球化学参数和热模拟实验产烃率数据为ＦＭＴ值定量评价煤生烃排烃潜力的适用性和有效性提供了佐证。  相似文献   

Experiments on the primary migration of oil from source rocks     

马素萍  雷天柱  荆明  夏燕青 《中国地球化学学报》2007,26(1):66-71

Simulation experiments on the primary migration of oil were carried out on massive samples. The results proved that oil generated from source rocks was expelled in the form of an independent oil phase. High oil-expulsion efficiency was observed. It follows that the primary migration of oil is not directly dependent on the quantity of oil generated from the source rocks. Therefore, the oil-expulsion proportion was high though some source rocks yielded only a limited amount of oil. A great deal of gas was produced at the same time of oil-generation. Thus, it can be concluded that the main expulsion energy for oil primary migration came from these gases.  相似文献   

超压盆地中泥岩的流体压裂与幕式排烃作用   总被引：37，自引：5，他引：32  

解习农  刘晓峰 《地质科技情报》1998,17(4):59-64

流体压裂是在异常高流体压力体系的低渗泥岩中流体活动的主要输导通道。流体压裂不仅导致低渗泥岩的幕式压实作用,而且为油气运移,储集的研究提供了新的理论模式。超压盆地泥岩的压实演化可划分为两个阶段,即连续压实和幕式压实阶段,其中幕式压实阶段又可根据导致流体压裂的主控因素进一步划分为两个亚阶段,即水力压裂和生烃压裂,前者主要由于泥岩欠压实和新生流体源的增压所致,后者则主要由于泥岩中有机质生烃及烃类裂解后增  相似文献   

西湖凹陷平北地区烃源岩特征及生排烃史     

陆俊泽  叶加仁  黄胜兵  吴娟 《海洋地质译丛》2009,(4):38-43

为了综合确定平北地区的主力烃源岩，深化其油气成藏动力学过程研究，在烃源岩分布特征及有机质丰度、类型和成熟度分析的基础上，应用舍油气盆地数值模拟技术，定量恢复了研究区主要烃源岩层系的生排烃历史。研究表明，平北地区主要发育始新统平湖组、渐新统花港组两套烃源岩系，其中平湖组暗色泥岩为主力烃源岩，具较高的有机质丰度、成熟度、生排烃强度与排烃效率；以平湖组为源岩的油气系统应是本区油气勘探的主要目标。  相似文献   

Hydrocarbon generation and expulsion characteristics of Lower Permian P1f source rocks in the Fengcheng area,northwest margin,Junggar Basin,NW China: implications for tight oil accumulation potential assessment     

Tao Hu  Xiongqi Pang  Sa Yu  Xulong Wang  Hong Pang  Jigang Guo  Fujie Jiang  Weibing Shen  Qifeng Wang  Jing Xu 《Geological Journal》2016,51(6):880-900

Combined with the actual geological settings, tight oil is the oil that occurs in shale or tight reservoirs, which has permeability less than 1 mD and is interbedded with or close to shale, including tight dolomitic oil and shale oil. The Fengcheng area (FA), at the northwest margin of the Junggar Basin, northwest China, has made significant progress in the tight oil exploration of the Fengcheng (P₁f) Formation recently, which indicates that the tight oil resources have good exploration prospects. Whereas the lack of recognition of hydrocarbon generation and expulsion characteristics of Permian P₁f source rocks results in the misunderstanding of tight oil resource potential. Based on the comprehensive analysis of geological and geochemical characteristics of wells, seismic inversion, sedimentary facies, tectonic burial depth, etc., the characteristics of P₁f source rocks were investigated, and the horizontal distributions of the following aspects were predicted: the thickness of source rocks, abundance and type of organic matter. And on this basis, an improved hydrocarbon generation potential methodology together with basin simulation techniques was applied to unravel the petroleum generation and expulsion characteristics of P₁f source rocks in FA. Results show that the P₁f source rocks distribute widely (up to 2039 km²), are thick (up to 260 m), have high total organic content (TOC, ranging from 0.15 to 4 wt%), are dominated by type II kerogen and have entered into low mature–mature stage. The modeling results indicate that the source rocks reached hydrocarbon generation threshold and hydrocarbon expulsion threshold at 0.5% Ro and 0.85% Ro and the comprehensive hydrocarbon expulsion efficiency was about 46%. The amount of generation and expulsion from the P₁f source rocks was 31.85 × 10⁸ and 15.31 × 10⁸ t, respectively, with a residual amount of 16.54 × 10⁸ t within the source rocks. Volumetrically, the geological resource of shale oil is up to 15.65 × 10⁸ t. Small differences between the amounts calculated by the volumetric method compared with that by hydrocarbon generation potential methodology may be due to other oil accumulations present within interbedded sands associated with the oil shales. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献