Modeling free gas content of the Lower Paleozoic shales in the Weiyuan area of the Sichuan Basin,China     

《Marine and Petroleum Geology》2014

Two sets of Lower Paleozoic organic-rich shales develop well in the Weiyuan area of the Sichuan Basin: the Lower Cambrian Jiulaodong shale and the Lower Silurian Longmaxi shale. The Weiyuan area underwent a strong subsidence during the Triassic to Early Cretaceous and followed by an extensive uplifting and erosion after the Late Cretaceous. This has brought about great changes to the temperature and pressure conditions of the shales, which is vitally important for the accumulation and preservation of shale gas. Based on the burial and thermal history, averaged TOC and porosity data, geological and geochemical models for the two sets of shales were established. Within each of the shale units, gas generation was modeled and the evolution of the free gas content was calculated using the PVTSim software. Results show that the free gas content in the Lower Cambrian and Lower Silurian shales in the studied area reached the maxima of 1.98–2.93 m³/t and 3.29–4.91 m³/t, respectively (under a pressure coefficient of 1.0–2.0) at their maximum burial. Subsequently, the free gas content continuously decreased as the shale was uplifted. At present, the free gas content in the two sets of shales is 1.52–2.43 m³/t and 1.94–3.42 m³/t, respectively (under a current pressure coefficient of 1.0–2.0). The results are roughly coincident with the gas content data obtained from in situ measurements in the Weiyuan area. We proposed that the Lower Cambrian and Lower Silurian shales have a shale gas potential, even though they have experienced a strong uplifting.  相似文献   

我国页岩气资源及影响因素          下载免费PDF全文

史长营  王峰  秦娜  王辉 《山东国土资源》2014,30(4):58-61

在世界面临能源短缺的背景下,页岩气作为油气勘探的一个新领域,越来越得到世界各国的重视。我国页岩气资源丰富,许多盆地或地区具有页岩气大规模成藏的地质条件,对页岩气的研究显得尤为重要。该文介绍了我国页岩气资源储量、分布及开采面临的问题,概述了页岩气地质特征。在此基础上探讨了我国页岩气的影响因素,认为我国页岩气主要受有机碳含量、成熟度、裂缝的发育程度、地层压力的控制;页岩气与煤层气同属于非常规天然气,其赋存形态、成因类型、富集规律具有很多相似之处,因此可将页岩气与煤层气进行对比研究。  相似文献   

美国近年来矿业发展与矿产资源管理基本情况     

何金祥 《国土资源情报》2014,(5):2-7

美国是世界矿产品生产大国,也是矿产品消费大国,其矿产资源政策与措施对世界矿产品市场有重要影响。本文简要介绍和讨论了美国主要矿产资源储量、主要矿产品产量、主要矿产品消费量、矿产品贸易、重要矿产品的对外依存度、矿业管理体制与基本制度、主要矿业管理机构与矿产资源管理的指导原则、主要矿业法律、矿业政策基本走向等。最后,笔者对美国矿产资源政策的战略核心进行了初步分析。  相似文献   

滇黔北下古生界海相页岩气藏赋存条件评价   总被引：11，自引：3，他引：8  

梁兴  叶熙  张介辉  舒红林  楼基胜  姚秋昌  王高成 《海相油气地质》2011,16(4):11-21

页岩气区域地质调查和钻探成果表明,滇黔北坳陷属于改造残留型构造坳陷,海相下志留统龙马溪组和下寒武统牛蹄塘组黑色页岩发育,单层厚度达50m以上.评价区页岩的厚度、埋深、TOC、含气性、力学性质、物性和矿物成分等评价参数与北美已商业开发页岩气田的具有一定相似性,具备形成页岩气藏的有利地质条件,是现实的页岩气勘探开发重要目的...  相似文献   

Role of the shale tectonics on the evolution of the Eastern Venezuelan Cenozoic thrust and fold belt     

Leo Duerto  Ken McClay 《Marine and Petroleum Geology》2011,28(1):81-108

This paper presents a structural and stratigraphic analysis of the foreland-fold-belt of the Eastern Venezuelan Basin and the main conclusions about shale tectonic mechanisms in the area. The deformation of the foreland-fold-belt has been investigated analyzing the growth strata architecture preserved on the structure fold limbs. Three contractional episodes are proposed for the Eastern Venezuelan Basin: 1) Oligocene to middle Miocene, 2) late Miocene to Pliocene and 3) Pleistocene. The first episode produced contractional listric faults inside the shale and long displacement blind thrusts in the underlying Cretaceous units. The second episode produced the deformation of the Cenozoic strata into overlapping east-west-trending, convex northward anticlines that covers more than 200 kilometers in length and 40 kilometers wide, break-through normal faults product of a high sedimentary load that overcomes contraction and the formation of short-displacement blind thrusts in the underlying Cretaceous units. The last episode is related to an oblique compression and the formation of high angle extensional faults with dextral movement and NW-SE strike. The role of the shale tectonics in the evolution implies that shale deforms in two stages: 1) folding and 2) normal faulting of the crest of the anticline (Break through normal faulting). Folding controlled the sediment distribution during most of the Neogene strata, while the normal faulting of the anticlines represent basin potential for hydrocarbon. The best potential hydrocarbon plays in the basin are related to oblique-collision restricted basins and controlled by break-through normal faults and the presence of NW-SE strike faults that connect the HC source with the reservoirs. Results from this research imply that the role of sedimentation is fundamental for the overburden sand distribution and tectonic constrain of the folds.  相似文献   

Distribution characteristics,exploration and development,geological theories research progress and exploration directions of shale gas in China     

Shi-zhen Li  Zhi Zhou  Hai-kuan Nie  Lei-fu Zhang  Teng Song  Wei-bin Liu  Hao-han Li  Qiu-chen Xu  Si-yu Wei  Shu Tao 《China Geology》2022,5(1):110-135

The shale gas resources in China have great potential and the geological resources of shale gas is over 100×10¹²m³,which includes about 20×10¹²m³ of recoverable resources.Organic-rich shales can be divided into three types according to their sedimentary environments,namely marine,marine-continental transitional,and continental shales,which are distributed in 13 stratigraphic systems from the Mesoproterozoic to the Cenozoic.The Sichuan Basin and its surrounding areas have the highest geological resources of shale gas,and the commercial development of shale gas has been achieved in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in these areas,with a shale gas production of up to 20×10⁹m³ in 2020.China has seen rapid shale gas exploration and development over the last five years,successively achieving breakthroughs and important findings in many areas and strata.The details are as follows.(1)Large-scale development of middle-shallow shale gas(burial depth:less than 3500 m)has been realized,with the productivity having rapidly increased;(2)breakthroughs have been constantly made in the development of deep shale gas(burial depth:3500-4500 m),and the ultradeep shale gas(burial depth:greater than 4500 m)is under testing;(3)breakthroughs have been made in the development of normal-pressure shale gas,and the assessment of the shale gas in complex tectonic areas is being accelerated;(4)shale gas has been frequently discovered in new areas and new strata,exhibiting a great prospect.Based on the exploration and development practice,three aspects of consensus have been gradually reached on the research progress in the geological theories of shale gas achieved in China.(1)in terms of deep-water fine-grained sediments,organic-rich shales are the base for the formation of shale gas;(2)in terms of high-quality reservoirs,the development of micro-nano organic matter-hosted pores serves as the core of shale gas accumulation;(3)in terms of preservation conditions,weak structural transformation,a moderate degree of thermal evolution,and a high pressure coefficient are the key to shale gas enrichment.As a type of important low-carbon fossil energy,shale gas will play an increasingly important role in achieving the strategic goals of peak carbon dioxide emissions and carbon neutrality.Based on the in-depth study of shale gas geological conditions and current exploration progress,three important directions for shale gas exploration in China in the next five years are put forward.  相似文献   

“Source-Diagenesis-Accumulation” enrichment and accumulation regularity of marine shale gas in southern China     

《China Geology》2018,1(3):319-330

After the breakthrough of shale gas exploration and development in the Ordovician Wufeng Formation (Fm.) and Silurian Longmaxi Fm. of Chongqing Jiaoshiba area, Changning-Weiyuan area, etc. in Sichuan basin, a series of discovery and breakthrough were obtained by China Geological Survey in the Cambrian Niutitang Fm. and Sinian Doushantuo Fm. shale of the areas with complicated structure outside Sichuan basin. Based on the understanding of the law of shale gas enrichment in Longmaxi Fm. in the basin, this paper puts forward three elements of the formation and enrichment of shale gas, which are the “Source”, the “Diagenesis” and the “Accumulation”, after deeply studying the law shale gas enrichment and accumulation in Sinian-Cambrian reservoir of the complex structure area outside the basin. The “Source” means the sedimentary environment and petrological characteristics of organic shale. The “Diagenesis” means the basin tectonic subsidence and hydrocarbon generation and expulsion process of organic matter. The “Accumulation” means the tectonic uplift and shale gas preservation. It is proposed that the Sinian-Cambrian and Ordovician-Silurian black shale series in the middle and upper Yangtze region of southern China were both formed in the deep-water shelf environment of rift trough and foreland basin respectively. The dessert intervals were formed in the strong reduction environment under transgressive system tract. The shale lithology belongs to calcium-siliceous and charcoal-siliceous respectively. Based on the summary of structural evolution in Yangtze area, the correlation of structural burial depth with shale diagenesis and the coupling evolution of organic matter with pore structure are discussed. Combining with structural styles, the preservation conditions of shale gas are discussed. Five types of shale gas reservoir control models are further described. Two types of future exploration directions, which are reverse fault syncline and paleo-uplift margin in complex structural area outside the basin, are proposed.  相似文献   

页岩气地震勘探中页岩各向异性的地震模拟研究          下载免费PDF全文

孙伟家  符力耘  管西竹  魏伟 《地球物理学报》2013,56(3):961-970

页岩的强各向异性特征挑战地震波传播数值模拟方法的精度极限, 特别是易引起频散的高频波(>100 Hz)传播的数值模拟.鉴于目前我国页岩气地震勘探主要以常规地震声波资料为主,本文首先介绍了一种VTI介质声波方程的任意偶数阶有限差分数值模拟方法,并讨论其稳定性条件和吸收边界条件.任意偶数阶的差分解可有效提高计算精度,压制数值频散噪声.针对页岩较强的各向异性特征,本文比较了不同模型的声波方程和VTI介质声波方程计算得到的地震响应.数值结果表明,各向异性对地震波的运动学(相位)和动力学(振幅)特性影响作用明显.因此,在页岩气地震勘探资料处理的各个环节必须充分考虑各向异性的影响,采取有别于常规油气勘探的处理流程和技术.  相似文献   

保山地区下仁和桥组页岩气成藏条件分析     

陈志柱  张宗羲  杨楠  白鹏 《云南地质》2014,(2):180-184

通过野外调查及室内测试,对云南省保山地区早志留世浅海较深水环境沉积的下志留统下仁和桥组黑色笔石页岩进行了分析研究.初步认为下仁和桥组黑色页岩沉积厚度大且稳定,有机质丰度高、岩石成熟度高、有机质类型好、演化程度高、裂缝发育,具备页岩气藏的形成条件.  相似文献   

湖南扬子地区志留系龙马溪组页岩气成藏条件及前景评价     

李国亮  王先辉  杨俊  刘天一  罗鹏 《华南地质与矿产》2014,(3):285-292

湖南地处扬子陆块和华夏古陆过渡区,湘西北地区至雪峰山东南缘基本位于扬子地台,此区域属南方海相页岩气远景区。本文主要选取地质构造条件优越、页岩气特征较为明显的龙马溪组黑色页岩层作为主要研究对象。研究表明,龙马溪组黑色页岩分布面积广、有机碳含量高(TOC平均值为2.0%)、热演化程度高(Ro平均值为2.59%)、低孔低渗(孔隙度平均值为2.3%、渗透率小于0.04×10-3μm2);黑色页岩产出厚度在石门-桑植复向斜至龙山、来凤一带较厚,基本大于30 m。而其整体埋深范围在1000~2000m之间为主,产出较为平缓。总体认为,此套含气页岩有待进一步详细勘探和研究,也是十分有开发潜力的页岩气目标层。优选区集中在石门-桑植复向斜至雪峰山东南缘。  相似文献