西昌盆地上三叠统白果湾组富有机质泥页岩沉积岩相古地理与孔隙特征

海陆过渡相富有机质泥页岩是页岩气勘查开发的重要领域。本文以西昌盆地上三叠统白果湾组富有机质泥页岩为研究对象,对研究区内富有机质泥页岩的沉积岩相古地理特征、微观孔隙类型、孔隙结构特征进行研究。白果湾组富有机质泥页岩段沉积相主要为湖泊相、三角洲相、河流相。发育不同类型的微孔隙,孔隙主要以小孔为主,微孔次之,平均孔径分布在5.56~56.89nm之间,比表面积平均为9.44m²/g,总孔体积平均为0.0187cm³/g。页岩气主要形成于滨浅湖亚相及半深湖亚相中,并主要吸附于富有机质泥页岩的小孔、微孔内;西昌盆地白果湾组富有机质泥页岩储集空间较好,具有良好的勘探潜力。     

四川西昌盆地三叠系沉积环境分析

在岩石地层划分的基础上,讨论了西昌盆地三叠系沉积相类型及特征。研究区南部及北部缺失T1-2及T3下部地层,仅中部发育较完整的三叠系。南部白果湾组主要发育沼泽、沼泽化湖泊及湖泊相。北部白果湾组包括沼泽相、沼泽化湖相及湖泊相。中部白果湾组沉积相为沼泽、沼泽化湖泊、河流、河湖三角洲及湖泊相,雷口坡组沉积相包含潮坪、湖、生物滩(丘)、广海陆棚相;嘉陵江组及飞仙关组分别以河口和河流相为主。     

阜新盆地沙海组三段浅层致密砂岩储层特征及成岩作用

针对阜新盆地浅层致密砂岩气成藏条件,在对8口井砂岩储层测试数据的分析基础上,研究了沙海组三段砂岩储层物性和沉积－成岩特征.认为阜新盆地沙海组三段砂岩储层为浅层致密砂岩储层,埋深<1500 m,孔隙度<10%,渗透率<1×10-3μm2;成岩作用控制沙海组三段砂岩的物性特征,沙海组三段砂岩主要经历压实作用、碳酸盐胶结作用和碳酸盐溶解作用,成岩阶段主要处于晚成岩A期.从而指出沙海组三段浅层致密砂岩储层适合储集来自周围气源岩生成的天然气,是盆地浅层致密砂岩气的有利勘探层位.     

下寺湾油田长2油层储层特征与油气成藏规律探讨

从鄂尔多斯盆地下寺湾油田长2油层地质特征及区域构造入手,分析研究长2油层的储层的孔隙结构及其成因,并进一步总结下寺湾油田长2的油藏类型、分布规律及其与岩性和构造的关系,从而提出下寺湾地区长2油层的富集规律。研究结果显示鄂尔多斯盆地下寺湾油区长2地层发育鼻状隆起带,储层以三角洲平原分流河道砂岩为主,多为细粒长石砂岩,成岩后生作用使得储层孔隙度、渗透率很低;下寺湾地区长2油藏类型主要为构造-岩性油藏和岩岩性油藏两种,北东东方向的鼻隆带、岩性上倾尖灭、岩性相变带和砂岩的中后期成岩作用对含油分布有着重要的控制作用。     

鄂尔多斯盆地镇泾油田致密砂岩长8储层特征及沉积相研究

利用扫描电镜、铸体薄片等多种方法,对鄂尔多斯盆地镇泾油田长8油层组低孔低渗的致密砂岩储层的储层特征和沉积相进行综合分析研究,发现该地区砂岩类型主要有细粒岩屑长石砂岩和长石岩屑砂岩,孔隙度和渗透率分别为3.9%%~11%和(0.04~0.55)×10-3μm2。研究区主要成岩作用包括压实作用、压溶作用、胶结作用、溶蚀作用、交代作用。通过对镇泾区块沉积储层形成的沉积相的研究,查明该区广泛发育三角洲相,进一步可划分为水下分流河道、水下天然堤、水下决口扇、水下分流间湾、河口坝等5种微相。上述研究为镇径油田长8段储层的研究和预测提供了理论依据。     

鄂尔多斯盆地西北部盒8段储层物性特征

鄂尔多斯盆地盒8段地层是长庆油田的重点产气层段之一。通过对盆地西北部盒8段岩心、薄片、铸体薄片和扫描电镜等观察,结测井等数据的分析,对其岩石学特征、孔隙类型、储层物性特征及其受控因素等进行了研究。结果表明,盒8段岩屑石英砂岩、石英砂岩主要孔隙类型为次生孔隙和晶间孔,孔隙度和渗透率高值区都主要集中在研究区西南部,并且两个高值区域十分接近,是下一步勘探和开发的有利区域。     

鄂尔多斯盆地下寺湾油田下组合储层特征分析

由于以往延长油田的油气勘探重点在上组合油层组,缺乏对下组合油层组的关注。在对鄂尔多斯盆地下寺湾油田的沉积相研究基础上,开展对下组合油层的研究,通过薄片鉴定、压汞曲线数据、扫描电镜资料、矿物成分鉴定等手段,分析研究储层孔隙特征,成岩作用以及物性特征等,研究得出下组合各层段砂岩主要为长石砂岩和岩屑长石砂岩;岩石孔隙类型主要为粒间孔、粒内溶孔,主要的孔喉组合为细小孔微细喉型。下组合储层物性整体较差,孔隙度主要分布范围5%~10%之间,渗透率分布在0.1~0.2 m D之间,属于特低孔、超低渗储层。     

西昌盆地白果湾组泥页岩储层特征及主控因素

海陆过渡相富有机质泥页岩已在国内多个区块取得重要突破,以西昌盆地上三叠统白果湾组富有机质泥页岩为研究对象,基于岩性特征,运用铸体薄片观察、厚度对比、有机地化、全岩X射线衍射、孔隙度、渗透率、扫描电镜、高压压汞、低温N₂吸附等技术手段,综合分析西昌盆地上三叠统泥页岩储层特征及其主控因素。结果表明：西昌盆地上三叠统白果湾组富有机质泥页岩有机碳含量介于0.3%～2.21%,平均为1.02%,有机质类型为Ⅱ₂型和Ⅲ型;有机质成熟度介于1.02%～3.87%。富有机质泥页岩的厚度介于30～110 m,脆性矿物含量较高,为11%～77%,平均为40.5%。孔隙度介于1.28%～9.02%,平均为4.03%,渗透率在(0.001 7～0.146)×10^-3 μm²之间,平均为0.03×10-3μm²。比表面积介于6.25～13.7 m²/g,平均为10.17 m²/g,平均孔径为6.66～9.79 nm。有机碳含量与孔隙度具正相关性,研究区内泥页岩...     

鄂尔多斯盆地东南部上古生界储层岩石学特征

为弄清鄂尔多斯盆地东南部上古生界砂岩储层岩石学特征的差异性,通过大量岩石薄片、扫描电镜、阴极发光和X衍射等分析化验资料,对研究区上古生界主要产气层段砂岩储层的岩石类型、成分特征、平面分布等进行了详细研究。结果表明,盒8段和山1段是以岩屑砂岩和岩屑石英砂岩为主,少量石英砂岩,岩屑主要为千枚岩,其次为石英岩、燧石和变质砂岩;山2段和本溪组则以石英砂岩为主,其次为岩屑石英砂岩,少量岩屑砂岩,其岩屑主要为石英岩,其次为燧石和千枚岩;从盒8段—本溪组的砂岩中碳酸盐和硅质胶结物含量均有逐渐增加的趋势,而高岭石和绿泥石含量逐渐减少。受物源分异的影响,从东部→西部→南部砂岩成分成熟度依次降低。     

贝尔凹陷与塔南凹陷下白垩统铜钵庙组南屯组油气储层特征及孔隙度控制作用

早白垩世铜钵庙-南屯组的火山岩和砂岩是中国海拉尔盆地贝尔凹陷和蒙古国塔木察格盆地塔南凹陷的主要油气储层.其中:铜钵庙组储层主要由火山碎屑岩组成;南屯组储层以砂岩为主,其次为火山碎屑岩.在铜钵庙组的火山碎屑岩中,贝尔凹陷主要为凝灰岩,塔南凹陷主要为沉凝灰岩和凝灰质砂岩.镜质体反射率和最高热解温度数据表明,成岩阶段主要为中成岩阶段A期.铜钵庙组-南屯组储层的孔隙类型主要为次生孔,其次为原生孔,属中低孔、特低渗型储层.贝尔凹陷和塔南凹陷均发育2个异常高孔隙带,储层孔隙度主要受储层岩石类型、沉积相和成岩作用控制.     

The Relationship between Jurassic Coal Measures and Sandstone-type Uranium Deposits in the Northeastern Ordos Basin, China

Outcrop and drill hole data show that the Jurassic coal measures in the northeastern Ordos Basin are composed mainly of the Yan'an Formation and the lowstand system tract of the Zhiluo Formation,and there is a regional unconformity between them. The Dongsheng uranium deposit is associated with the Jurassic coal measures. Research data indicate that the Jurassic coal measures in the study area have a certain hydrocarbon-generating capacity,although the metamorphic grade is low(Ro=0.40%–0.58%). In the Dongsheng region alone,the accumulative amount of generated coalbed methane(CBM) is about 2028.29 × 108 –2218.72 × 108 m~3; the residual amount is about 50.92 × 108 m~3,and the lost amount is about 1977 × 108 m~3. Analysis of the burial history of the host rocks and the evolutionary history of the Dongsheng uranium deposit suggests that the Jurassic coal measures generated hydrocarbon mainly from Middle Jurassic to Early Crataceous,which is the main mineralization phase of the Dongsheng uranium deposit. By the Late Cretaceous,a mass of CBM dissipated due to the strong tectonic uplift,and the Dongsheng uranium deposit stepped into the preservation phase. Therefore,the low-mature hydrocarbon-containing fluid in the Jurassic coal measures not only served as a reducing agent for the formation of sandstone-type uranium deposits,but also rendered the second reduction of paleo-interlayer oxidation zone and become the primary reducing agent for ore conservation. Regional strata correlation reveals that the sandstone-type uranium reservoir at the bottom of the Zhiluo Formation is in contact with the underlying industrial coal seams in the Yan'an Formation through incision or in the form of an unconformity surface. In the Dongsheng region with poorly developed fault systems,the unconformity surface and scour surface served as the main migration pathways for low-mature hydrocarbon-containing fluid migrating to the uranium reservoir.     

应用盆地模拟技术评价西藏伦坡拉盆地油气资源潜力

伦坡拉盆地是西藏地区唯一取得工业油流的含油气盆地,由于地质条件复杂,油质偏稠,导致油气勘探进展缓慢。为了明确盆地油气资源潜力,有效指导下一步勘探方向,文章结合新钻探及地震资料,运用盆地模拟方法开展埋藏史、热史及生烃史研究,计算了盆地古近系生烃量和资源量。结果表明伦坡拉盆地古近系生烃量为49.80×108 t,资源量为1.507×108 t。其中以蒋日阿错为最大生烃中心,生烃量20.93×108 t,资源量1.05×108 t,江加错和爬错北部为次重要生烃中心,生烃量分别为8.83×108 t和14.76×108 t,资源量分别为0.41×108 t及0.71×108 t。从模拟结果可知,蒋日阿错洼陷、江加错洼陷资源丰度相对较高,为油气资源富集有利区,爬错洼陷由于烃源和圈闭条件较差,目前仅发现罗玛迪库构造圈闭,资源丰度较低。应用盆地模拟明确了伦坡拉盆地油气资源构成和油气资源分布有利区带,为下一步勘探指明了方向。      

Critical conditions for natural gas charging and delineation of effective gas source rocks for tight sandstone reservoirs

Although it has been shown that the potential of tight‐sand gas resources is large, the research into the mechanisms of hydrocarbon charging of tight sandstone reservoirs has been relatively sparse. Researchers have found that there is a force balance during hydrocarbon charging, but discriminant models still have not been established. Based on the force balance conditions observed during gas migration from source rocks to tight sandstone reservoirs, a calculation formula was established. A formula for identifying effective source rocks was developed with the gas expulsion intensity as the discrimination parameter. The critical gas expulsion intensity under conditions of various burial depths, temperatures, and pressures can be obtained using the calculation formula. This method was applied in the Jurassic tight sandstone reservoirs of the eastern Kuqa Depression, Tarim Basin, and it was calculated that the critical expulsion intensity range from 6.05 × 10⁸ m³/km² to 10.07 × 10⁸ m³/km². The critical gas charging force first increases with depth and later decreases with greater depths. The distribution range of effective gas source rocks and total expelled gas volume can be determined based on this threshold. This method provides new insight into and method for predicting favourable tight‐sand gas‐bearing regions and estimating their resource potentials. Copyright © 2014 John Wiley & Sons, Ltd.     

Geothermal investigations in the Upper Vindhyan sedimentary rocks of Shivpuri area,central India

Heat flow has been determined by combining temperature measurements in 7 boreholes with thermal conductivity measurements in the Upper Vindhyan sedimentary rocks of Shivpuri area, central India. The boreholes are distributed at 5 sites within an area of 15 × 10 km²; their depths range from 174 to 268 m. Geothermal gradients estimated from borehole temperature profiles vary from 8.0–12.7 mK m⁻¹ in the sandstone-rich formations to 25.5–27.5 mK m⁻¹ in the shale-rich formations, consistent with the contrast in thermal conductivities of the two rock types. Heat flow in the area ranges between 45 and 61 mW m⁻², with a mean of 52±6 mW m⁻². The heat flow values are similar to the >50 mW m⁻² heat flow observed in other parts of the northern Indian shield. The heat flow determinations represent the steady-state heat flow because, the thermal transients associated with the initial rifting, convergence and sedimentation in the basin as well as the more recent Deccan volcanism that affected the region to the south of the basin would have decayed, and therefore, the heat flow is in equilibrium with the radiogenic heat production of the crust and the heat flow from the mantle. The present study reports the heat flow measurements from the western part of the Vindhyan basin and provides heat flow information for the Bundhelkhand craton for the first time. Radioelement (Th, U and K) abundances have been measured both in the sedimentary rocks exposed in the area as well as in the underlying basement granite-gneiss of Bundelkhand massif exposed in the adjacent area. Radioactive heat production, estimated from those abundances, indicate mean values of 0.3 μW m⁻³ for sandstone with inter-bands of shale and siltstone, 0.25 μW m⁻³ for sandstone with inter-bands siltstone, 0.6 μW m⁻³ for quartzose sandstone, and 2.7 μW m⁻³ for the basement granitoids. With a total sedimentary thickness not exceeding a few hundred metres in the area, the heat production of the sedimentary cover would be insignificant. The radioactive heat contribution from the basement granitoids in the upper crust is expected to be large, and together with the heat flow component from the mantle, would control the crustal thermal structure in the region.     

四川海相克拉通盆地显生宙演化阶段及其特征

四川叠合盆地是在四川海相克拉通盆地基础上形成的。本文利用最新的钻井资料、地震资料及其研究成果,详细阐述了四川海相克拉通盆地在显生宙的演化阶段及其特征。研究结果发现,四川海相克拉通盆地显生宙演化可分为早晚两期,早期为晚震旦世-石炭纪,晚期为二叠纪-中三叠世。两期克拉通演化都经历了早期弱拉张,后期弱挤压阶段。弱拉张初始阶段都有一次海相碳酸盐岩的大面积稳定沉积(震旦系灯影组和二叠系栖霞-茅口组)和随后的隆升剥蚀作用及风化壳岩溶作用。其后进入弱拉张期,发育拉张槽,拉张强度最大的部位均位于克拉通的西北部,都是从克拉通的西北部边缘向克拉通内部减弱。然而,两期拉张槽的充填特征不同,早寒武世绵阳-长宁拉张槽是补偿型充填,与拉张槽周缘相比,拉张槽内沉积厚度巨大;晚二叠世-早三叠世开江-梁平拉张槽为欠补偿型充填,与拉张槽周缘相比,拉张槽内沉积厚度非常薄。拉张期结束后进入弱挤压阶段,形成古隆起,挤压强度最大的部位均位于克拉通的西南部,都是从克拉通的西南边缘向克拉通内部减弱。弱拉张阶段的拉张槽与弱挤压阶段的古隆起均为大角度相交关系;然而,拉张槽和古隆起的规模差别较大,早寒武世绵阳-长宁拉张槽面积约5.4×10~4km~2,对应的加里东期乐山-龙女寺古隆起面积6×10~4km~2;晚二叠世-早三叠世开江-梁平拉张槽面积约2.0×10~4km~2,对应的印支期开江古隆起面积0.8×10~4km~2;晚二叠世-早三叠世蓬溪-武胜拉张槽面积约1.5×10~4km~2,对应的印支期泸州古隆起面积4.2×10~4km~2。绵阳-长宁拉张槽的规模比开江-梁平拉张槽、蓬溪-武胜拉张槽要大,乐山-龙女寺古隆起的规模也大于泸州-开江古隆起的规模。四川海相克拉通盆地显生宙演化特征在很大程度上控制了四川叠合盆地海相油气地质条件的发育和油气藏的形成分布。     

A study on hydrocarbon generation potential of deep source rocks and gas sources in Changling Fault Depression,Songliao Basin

Through natural gas exploration in the Changling Fault Depression,abundant natural gas flows were obtained and high-quality source rocks were also reveiled.Based on bulk analyses,organic matter abundance,organic matter type and thermal maturity of the source rocks were studied systematically.At the same time,gas gener-ating intensity and gas generating quantity were quantitatively analyzed by using basin modeling technologies.The results indicated that gas source rocks of the Shahezi Formation are characterized by abundant organic matter and dark mudstone distributions and high-over thermal maturity.They possess high gas generating intensity with the biggest value surpassing 500×108 m3/km2,and large gas generating quantity,accounting from 74.40% of the total amount.The Yingcheng Formation has good gas-source rocks with moderate dark mudstone and relatively high organic matter.It has type-Ⅲ organic matter and low-over thermal maturity.The gas generating intensity is moderate,between 20×108 and 60×108 m3/km2.The gas generating quantity is 13.63% of the total amount.The Huoshiling Formation has relatively good source rocks with limited dark mudstone and low organic matter.It has type-Ⅲ kerogen and over-thermal maturity.The gas generating quantity is 7.10% of the total amount.The Denglouku Formation has poor-gas source rocks,and is characterized by undeveloped dark mudstone and low organic matter abundance.It has type-Ⅲ organic matter and low-high thermal maturity.Hydrocarbon gases in the Changling Fault Depression mainly originated from the Shahezi Formation,and secondarily from the Yingcheng Formation.The contribution of the Huoshiling Formation gas source rocks is relatively small.     

河南省地热资源综合评价

河南省地热资源类型按照所处的大地构造环境分为沉积盆地型和隆起山地型。计算结果表明,沉积盆地区4 000 m以浅储存的地热水总量为82 063.23×10~8 m~3,储存热能总量为7 734 086.01×10~(12) kJ。不考虑回灌时,全省沉积盆地型地热可采流体量为92 223.93×10~4 m~3/a,可利用热能量196.6×10~(12) kJ/a;考虑回灌时,全省沉积盆地型地热流体可开采量5 931 841.92×10~4 m~3/a,可利用热能量为13 003.47×10~(12) kJ/a。统计分析显示,按地热流体可采量为92 223.93×10~4 m~3/a、地热流体可开采热量196.46×10~(12) kJ/a计算,即使按50%利用,其经济效益也是十分可观的。另外,地热开发可带动第三产业经济的发展,产生的间接经济效益更加巨大。     

孤岛油田馆陶组热储地热资源开发利用分析

孤岛油田蕴藏丰富的中、低温地热资源,对其进行合理的开发利用,对推进该区新、旧热能转换,促进地方经济发展具有重要意义。在总结以往勘探成果的基础上,查明了孤岛油田为大地热流高值异常区,平均值为72.62 mW/m²。重点研究馆陶组热储地热地质条件,查明了馆陶组下段热储厚度为106~145 m,平均孔隙度约为30%,热储温度为75.5~82 ℃,单位降深涌水量为3.71~10.55 m³/(h·m),是地热资源开发的有利目标热储。采用热储法估算区内馆陶组下段热储中蕴藏的地热资源量为3.745×10¹⁸ J,折合标准煤量1.28亿t,地热水储存量约为60.87×10⁸ m³; 采用开采强度法估算的该区地热水允许开采量约为253万m³/a,可支持供暖面积约100万m²。     

Increased hydrocarbon recovery and CO2 storage in Neogene sandstones,a Croatian example: part II

During 2003–2006, a pilot project of alternating water and CO₂ injection was performed on a limited part of the Upper Miocene sandstone oil reservoir of the Ivani? Field. During the test period oil and gas recovery was significantly increased. Additionally 4,440 m³ of oil and 2.26 × 10⁶ m³ of gas were produced. It has initiated further modelling of sandstone reservoirs in the Ivani? Field in order to calculate volumes available for CO₂ injection for the purpose of increasing hydrocarbon production from depleted sandstone reservoirs in the entire Croatian part of the Pannonian Basin System. In the first phase, modelling was based on results of laboratory testing on the core samples. It considered applying analogies with world-known projects of CO₂ subsurface storage and its usage to enhance hydrocarbon production. In the second phase, reservoir variables were analysed by variograms and subsequently mapped in order to reach lithological heterogeneities and to determine reliable average values of reservoir volumes. Data on porosity, depth and reservoir thickness for the “Gamma 3” and the “Gamma 4” reservoirs, are mapped by the ordinary kriging technique. Calculated volume of CO₂ expressed at standard condition which can be injected in the main reservoirs of the Ivani? Field at near miscible conditions is above 15.5 billion m³.