鄂尔多斯盆地苏里格气田储层成岩作用与模拟

通过苏里格气田气层与非气层的岩石学特征、成岩作用、储集特征对比,分析了气层与非气层成岩相的差异。气层主要发育在粗粒岩屑石英砂岩溶孔成岩相和含泥粗粒岩屑石英砂岩溶孔相中,非气层则主要发育在含泥(中)细粒岩屑石英砂岩致密压实相和含泥(中)粗粒岩屑石英砂岩残余粒间孔相中。通过流体-岩石相互作用物理和数学模拟,在成岩演化中成岩阶段A期,大量有机酸的排出,溶蚀了苏里格气田储层凝灰质和长石等易溶组分,形成次生孔隙。由于沉积水体能量强弱差别、成岩作用的不同,中粗粒与细粒沉积物成岩演化途径不同,中粗粒沉积物次生孔隙发育,残余一定的原生孔隙,总孔隙度较大,易形成气层;细粒沉积物原生孔隙消失殆尽,次生孔隙少,总孔隙度很小,不易形成气层。     

鄂尔多斯盆地地下水勘查

鄂尔多斯盆地矿产资源丰富,生态环境脆弱,地下水资源分布不均,水质复杂。在研究盆地周边岩溶区岩溶发育规律,地下水富集规律,地下水的补给、径流、排泄条件的基础上,将周边岩溶区划分为9个岩溶水系统,进一步划分为25个岩溶水子系统。白垩系自流盆地初步揭示了深部赋存有丰富的地下水,地下水受岩相古地理、地下水补径排条件等控制,水质差异较大。总结了东部黄土覆盖区的地下水类型及开发利用模式     

鄂尔多斯盆地油气发现历史回顾与经验教训(一)——从鄂尔多斯漫长找油气史看李四光1968年底谈话的历史意义

鄂尔多斯盆地油气勘探历史漫长, 新中国成立之前, 盆地内只开展了少量的油气勘探工作, 大量系统的石油地质调查和勘探开始于新中国成立之后。在1955-1968年的14年间, 虽然积累了大量地质资料和寻找油气的经验教训, 但既未发现工业油气流, 也没有提出可以肯定能发现油气的地区或目标。自1969年起, 遵照李四光"打回老家去"的指示精神, 石油普查工作从渭河与河套外围地堑转回鄂尔多斯大盆地, 先后在庆阳、华池、吴旗地区发现了6个侏罗系油田, 在延安-吴旗以北发现了5个亿吨级大油田, 在盆地中部发现了奥陶系陕北大气田。鄂尔多斯盆地油气发现历史表明, 油气的发现来自于地质学家的观念, 应重视以地质锤和放大镜起家的基础地质工作, 地质调查方法应用及勘查程序上必须有针对性, 既不能把复杂问题简单化, 也不能将特殊问题一般对待, 应按照实际情况确定选区方针, 发现问题并解决问题。      

鄂尔多斯盆地东部的油气运移

利用泥岩压实作用和蒙脱石成岩转化规律分析了鄂尔多斯盆地东部的油气运移，并在阐述区内油气运移史的基础上，预测了各时代、各成因类型油气的富集区块，探讨了运移机制。     

鄂尔多斯盆地苏里格大气区天然气近源运聚的证据剖析

鄂尔多斯盆地苏里格气区是中国最大的非常规连续型致密砂岩大气区,探讨其天然气分布与聚集机制可为非常规致密砂岩气的勘探提供理论依据。研究区地球化学方面的直接证据和储层、古构造背景等方面的间接证据包括:天然气主要分布在生气强度高值区,天然气组分未发生明显的混合效应,含气饱和度远离源岩明显减少,天然气碳同位素反映与原地烃源岩来源相同、成熟度一致的特征;储层经历了强烈的压实、硅质胶结和钙质胶结3种主要的致密化成岩作用,储层完成致密化过程、形成低孔渗、细孔喉致密储层的时间(R_o小于1.3%,早白垩世早期)要早于天然气大量生成的时间(R_o为1.5%~2.5%,早白垩世早期到晚白垩世初期);晚侏罗世到现今古构造坡降都较为平缓,缺乏形成较高垂直连续气柱的条件,综合多方面的证据,论证了现今苏里格大气区天然气分布聚集为近源短距离运聚的结果。     

鄂尔多斯盆地上古生界天然气藏类型辨析

针对鄂尔多斯盆地上古生界天然气藏是否为深盆气藏的问题,从成藏条件、成藏期次和气水分布特征等方面与典型的加拿大阿尔伯达深盆气藏进行综合对比。研究结果表明鄂尔多斯盆地上古生界气藏烃源岩分布广泛、生气中心不明显、生气速率较低、持续供气条件较差且供气分散,难以形成满足深盆气藏气驱水的动力;储层物性差、非均质性强、展布方向与构造走向一致且上倾方向为物性较差的致密层,不具备深盆气藏储层向上倾方向物性变好的条件;源储配置样式为"自生自储"式和"垂向叠置"式,由于砂体规模小、分布不连续,源储接触局限,不具备深盆气藏源储大面积接触的特征;天然气发生3期成藏,在盆地埋藏期与抬升期均可成藏,成藏时间较早,后期气藏调整改造强烈,不具备深盆气藏的保存条件。气水分布主要受储层物性和区域构造控制,分布复杂、分异不明显,没有气驱水形成的"气水倒置"界面。成藏特征综合对比分析表明鄂尔多斯盆地上古生界气藏并非深盆气藏,应为主要由储层物性控制的岩性气藏,该区油气勘探应以优质储层研究为重点。     

鄂尔多斯盆地油气地质的古地磁研究

古地磁研究结果表明，鄂尔多斯盆地寒武纪－早中奥陶世位于北纬１４°～２０°的古纬度区内，气候温暖潮湿，其南部和北部边缘的滨浅海相地层中可能富含生物有机质，是寻找该时期油气资源的有利地区；晚奥陶世－早石炭世，它可能经历了大规模的南北向水平构造迁移；晚石炭世－二叠纪，盆地处于北纬２０°左右地区，广泛发育的湖沼相沉积地层是煤成油、气的主要源岩层；三叠纪－侏罗纪，它位于北纬２４°～３１°，干湿交替的气候环境和差异构造旋转作用，为盆地边缘的油气形成和聚集创造了良好条件，因此有希望找到更多的中生代油气资源。     

鄂尔多斯盆地油气发现历史回顾与经验教训(二)——从盆地风格看盆地油气勘探前景

鄂尔多斯(陕甘宁)盆地是中国近代找油最早的地区之一。因长期不认识前陆盆地结构特点,加之主要勘探目标层三叠系延长组超低孔渗,因而油气勘探工作长期处于"孔孔见油,孔孔不流"的苦恼中。近二十年来,伴随着压裂技术及三角洲认识的开辟,前陆找油气相继在中国西部几个大盆地中都取得了进展。不过中国对前陆盆地的研究尚处于中早期阶段,应从前陆共性进一步加强研究,中国西部前陆油气勘探进一步繁荣是理所当然的趋势。     

云南喜山期断陷盆地特征与油气勘探方向——以保山盆地和曲靖盆地为例

在喜山期构造运动影响下,云南地区形成众多断陷盆地和拉分盆地。保山盆地和曲靖盆地是已经取得油气勘探突破的两个断陷盆地。两个盆地形态相似,均为受控盆断裂拉张、坳陷形成的一侧陡坡、一侧缓坡的箕状盆地。盆地演化均经历了拉张期、断陷期、坳陷期和抬升消亡期4个阶段。曲靖盆地受喜山运动二幕影响,缺失中新统地层沉积。烃源岩主要由盆地断陷和坳陷期半深湖-深湖相暗色泥岩和沼泽平原相煤系地层组成,有机碳含量1%~2%,有机质成熟度低。储层主要由盆地陡坡带冲洪积砂砾岩、三角洲前缘砂岩和三角洲平原水下分支河道砂体组成,具有高孔隙度低渗透率特点。鉴于断陷盆地烃源岩和储集层分布规律,在油气勘探过程中除了寻找有利的构造气藏外,应注重生烃坳陷内寻找有利的岩性气藏,有利相带为靠近陡坡带的冲洪积相和缓坡带的三角洲前缘相。     

A Volumetric Model for Evaluating Tight Sandstone Gas Reserves in the Permian Sulige Gas Field,Ordos Basin,Central China

To accurately measure and evaluate reserves is critical for ensuring successful production of unconventional oil and gas. This work proposes a volumetric model to evaluate the tight sandstone gas reserves of the Permian Sulige gas field in the Ordos Basin. The reserves can be determined by four major parameters of reservoir cutoffs, net pay, gas-bearing area and compression factor Z, which are controlled by reservoir characteristics and sedimentation. Well logging, seismic analysis, core analysis and gas testing, as well as thin section identification and SEM analysis were used to analyze the pore evolution and pore-throat structure. The porosity and permeability cutoffs are determined by distribution function curve,empirical statistics and intersection plot. Net pay and gas-bearing area are determined based on the cutoffs, gas testing and sand body distribution, and the compression factor Z is obtained by gas component. The results demonstrate that the reservoir in the Sulige gas field is characterized by ultralow porosity and permeability, and the cutoffs of porosity and permeability are 5% and 0.15×10~(–3) μm~2, respectively. The net pay and gas-bearing area are mainly affected by the sedimentary facies, sand body types and distribution. The gas component is dominated by methane which accounts for more than 90%, and the compression factor Z of H_8(P_2h_8) and S_1(P_1s_1) are 0.98 and 0.985, respectively. The distributary channels stacked and overlapped, forming a wide and thick sand body with good developed intergranular pores and intercrystalline pores. The upper part of channel sand with good porosity and permeability can be sweet spot for gas exploration. The complete set of calculation systems proposed for tight gas reserve calculation has proved to be effective based on application and feedback. This model provides a new concept and consideration for reserve prediction and calculation in other areas.     

Diagenesis and Their Succession of Gas-bearing and Non-gas-bearing Reservoirs in the Sulige Gas Field of Ordos Basin,China

Abstract: Comparisons have been made among lithology, diagenesis, and reservoir characteristics of gas-bearing and non-gas-bearing ones in the Sulige gas field of the Ordos Basin based on the laboratory analysis of thin sections, scanning electron microscope, and liquid inclusion of the reservoirs. The reservoirs of the Sulige gas field are now in the middle stage of diagenesis and have undergone compaction, cementation and dissolution. The secondary pore of the reservoir originated from the dissolution of the feldspar and tuff because of the organic acid action from the source rocks during the diagenetic middle stage. Gas-bearing reservoirs are common in soluble pore diagenetic facies of coarse detritus quartzose sandstone, whereas non-gas-bearing ones are common in tense compaction diagenetic facies of mud-bearing medium-fine detritus quartzose sandstone and residual intergranular pore diagenetic facies of mud-bearing medium-coarse detritus quartzose sandstone. The secondary pore is developed in gas-bearing reservoirs of the Sulige gas-field as the medium-coarse grain reservoirs formed in a powerful sedimentary environment and experienced strong dissolution. However, the sediments of fine grain size form the non-gas-bearing reservoirs because of less residual primary pore and secondary pore.     

鄂尔多斯盆地华庆地区侏罗系富县组油藏主控因素研究

侏罗系是鄂尔多斯盆地石油勘探与开发的重要目的层。华庆地区富县组油藏是近年鄂尔多斯盆地侏罗系勘探取得重大突破的新区块和新层系,已展现出良好的勘探前景和资源潜力。本文利用印模法等方法精细刻画了华庆地区前侏罗纪古地貌特征,深入分析了侏罗系富县组油藏控制因素和富集规律。结果表明,华庆地区侏罗系富县组油藏主要来源于下部三叠系延长组优质烃源岩,油藏类型为构造油藏和岩性-构造油藏,发育在古地貌斜坡带背景之上的河道边滩沉积主砂带内。油藏富集主要受控于前侏罗纪古地貌特征,充足的油源供给、河道边滩相沉积、优越的输导条件、鼻隆构造及良好的泥岩封堵等是华庆地区富县组油藏富集的主要控制因素。     

鄂尔多斯盆地东缘煤系页岩气储层特征评价

以鄂尔多斯盆地东缘石炭-二叠系富有机质泥页岩为研究对象,基于大量的钻孔泥页岩采样和分析测试,分区分层段对页岩气储层特征进行了评价。结果表明:鄂尔多斯盆地东缘石炭-二叠系富有机质暗色泥页岩广泛发育,泥页岩总厚度为90m左右,有机碳含量为1. 5%~5%,为Ⅲ型高成熟-过成熟状态的有机质;泥页岩脆性指数平均为31. 7%~42. 6%;储层具有微小的孔隙结构,平均孔径12. 2nm,平均比表面积6. 8m^2/g,平均孔体积0. 017cm^3/g,孔隙度为0. 82%~5. 91%;多数泥页岩样品的兰氏体积小于1m^3/t;总体而言,研究区页岩气源岩和储层物性条件良好,但含气量偏低。     

鄂尔多斯盆地中及上三叠统延长组沉积相与油气勘探的突破

鄂尔多斯盆地位于中国的中西部,跨陕、甘、宁、蒙、晋5省区,盆地本部面积25万km2.中及上三叠统延长组在盆地内广为展布,厚逾千米,发育冲积扇、河流、三角洲、湖泊等沉积相,是该地区重要的油气产层.根据盆地腹地100多口井的钻井资料及盆地周边地区的露头资料,以及长庆油田长时期对延长组的油气勘探经验,编制出了鄂尔多斯盆地中及...     

The characteristics and sources of natural gases from Ordovician weathered crust reservoirs in the Central Gas Field in the Ordos Basin

The Central Gas Field is a famous large-sized gas field in the Ordos Basin of China. However, identification of main gas sources of the Ordovician reservoirs in this gas field remains puzzling. On the basis of a lot of geochemical data and geological research on natural gases, the characteristics and sources of natural gases from Ordovician weathered crust reservoirs in the Central Gas Field in the Ordos Basin were studied. The results indicated that natural gases from Ordovician weathered crust reservoirs in the Central Gas Field in the Ordos Basin have similar chemical and isotopic compositions to highly mature and over-mature dry gases. Both coal-derived gases and oil-type gases coexist in the Central Gas Field in the Ordos Basin. The former was derived mainly from Carboniferous-Permian coal measures and the latter from Lower Paleozoic marine carbonates. It is suggested that coal-derived gases occur in the eastern part of the Central Gas Field while oil-type gases may be produced mainly in the northern, western and southern parts of the Central Gas Field in the Ordos Basin.     

鄂尔多斯盆地苏里格气田苏20区块山1段气层特征研究

通过分析地震反射特征及AVO响应特征,结合监督模式识别、CM油气检测等地震属性,系统地对苏里格气田苏20区内主要目的层山1段气层特征进行综合研究。认为山1段气层在区内分布较为广泛,且主要受岩性控制,含气地层在地震剖面上主要表现为较强振幅中-低频反射与较弱振幅中-低频反射,AVO响应主要表现为近道强远道弱的特征。此外,除已知的中西部及东南部天然气富集区,研究区的北部及西南部地区均发育有一定规模的岩性气藏,为区内下一步的勘探重点。     

鄂尔多斯盆地晚古生代沉积体系演化与煤成气藏

笔者在研究鄂尔多斯盆地晚古生代沉积体系的基础上,对晚古生代生烃源岩、储集层、盖层形成与展布进行了分析,提出了沉积体系对煤成气藏的控制作用;并认为盆地内部晚古生代煤成气藏是地层封闭的岩性气藏,储集体的分布主要受河流-三角洲沉积体系的控制,特别是山2期和盒9期的河流-三角洲沉积体系的控制,它们是盆内晚古生代煤成气藏的主力气层。     

鄂尔多斯盆地直罗油田长8 油层组储层特征研究

本文应用岩石薄片?铸体薄片?扫描电镜?压汞实验等测试分析资料,对直罗油田延长组长8 油层组储层的岩石学特征?物性特征?孔喉结构及孔喉类型等进行深入研究,试图探明该储层储集性能,为该区的勘探工作打好基础?结果表明,以水下分支河道沉积为主体的长8 油层组储集砂体主要为长石砂岩?岩屑长石砂岩,成分成熟度较低,结构成熟度中等;储集空间为粒间孔?粒内溶孔和晶间孔;储层物性较差,为典型的低孔低渗储层?物源方向?沉积相的展布控制了储层平面上的物性;垂向上压实作用和胶结作用对储层物性起破坏作用,溶蚀作用则对储层物性的改善有建设作用?