鄂尔多斯盆地南部张家滩油页岩生烃演化特征

鄂尔多斯盆地南部上三叠统延长组张家滩油页岩不仅是重要的固体矿产资源,也是该盆地三叠系油气的主力烃源岩。对张家滩油页岩典型露头剖面、钻井岩心进行有机碳含量（TOC）、氯仿沥青“A”及族组分、含油率等相关测试分析表明,张家滩油页岩有机质丰度高,TOC介于5.11%~36.47%,平均16.15%,生烃潜量（S₀+S₁+S₂）介于16.58~230.98 mg/g,平均94.20 mg/g,氯仿沥青“A”介于0.42%~2.22%之间,平均1.25%,属于生烃条件极好的优质烃源岩;含油率高,介于3.52%~14.6%之间,平均8.16%,属于中高品质的油页岩;干酪根类型以Ⅰ—Ⅱ₁型为主,R_o介于0.43%~1.09%。综合利用野外露头剖面和钻井岩心样品,建立了盆地南部张家滩油页岩的热演化剖面,分析了氯仿抽提前、后油页岩的含油率变化及油页岩热演化过程中含油率、热解烃产物的变化特征,揭示鄂尔多斯盆地南部张家滩油页岩具有聚集油页岩、页岩油两类资源的潜力,提出了相应的勘探开发对策。     

Reduction of sulfur content in shale oil by oxidative desulfurization

The oxidative desulfurization of shale oil obtained by thermal extraction of organic matter from shale rock using an oxidative catalytic system composed of hydrogen peroxide, a molybdenum salt, and acids of different natures has been studied. It has been shown that the application of this method in combination with extraction of the oxidation products of organic sulfur compounds makes it possible to remove up to 94% of total sulfur from the synthetic oil.     

Modeling of oil production by gravity drainage

Gravity drainage is one of the most effective mechanisms of developing an oil field because of high oil recovery yielded. There have been several models to characterize and model the process of gravity drainage. However the existing models do not work well in many cases. In this study, an analytical model was developed to determine the ultimate oil recovery by free-fall gravity drainage. This model demonstrates clearly the effect of capillary pressure on ultimate oil recovery. The ultimate oil recovery increases with the decrease in entry capillary pressure and the increase in pore size distribution index. The model was modified based on the ultimate recovery model to match and predict oil production. The model was tested against experimental, numerical, and field data of oil production by free-fall gravity drainage. The results demonstrated that the modified oil recovery model could work satisfactorily in the oil–gas cases studied. Initial oil production rate, entry capillary pressure, and average residual oil saturation can be estimated using the oil recovery model. An approach was also developed to infer capillary pressure curves from the oil production data by free-fall gravity drainage.     

Exploitation of fractured shale oil resources by cyclic CO_2 injection

With shale oil reservoir pressure depletion and recovery of hydrocarbons from formations, the fracture apertures and conductivity are subject to reduction due to the interaction between stress effects and proppants. Suppose most of the proppants were concentrated in dominant fractures rather than sparsely allocated in the fracture network, the fracture conductivity would be less influenced by the induced stress effect. However, the merit of uniformly distributed proppants in the fracture network is that it increases the contact area for the injection gas with the shale matrix. In this paper, we address the question whether we should exploit or confine the fracture complexity for CO_2-EOR in shale oil reservoirs. Two proppant transport scenarios were simulated in this paper: Case 1—the proppant is uniformly distributed in the complex fracture system, propagating a partially propped or un-propped fracture network; Case 2—the proppant primarily settles in simple planar fractures. A series of sensitivity studies of the fracture conductivity were performed to investigate the conductivity requirements in order to more efficiently produce from the shale reservoirs. Our simulation results in this paper show the potential of CO_2 huff-n-puff to improve oil recovery in shale oil reservoirs. Simulation results indicate that the ultra-low permeability shales require an interconnected fracture network to maximize shale oil recovery in a reasonable time period. The well productivity of a fracture network with a conductivity of 4 mD ft achieves a better performance than that of planar fractures with an infinite conductivity. However, when the conductivity of fracture networks is inadequate,the planar fracture treatment design maybe a favorable choice. The available literature provides limited information on the relationship between fracture treatment design and the applicability of CO_2 huff-n-puff in very low permeability shale formations. Very limited field test or laboratory data are available on the investigation of conductivity requirements for cyclic CO_2 injection in shale oil reservoirs. In the context of CO_2 huff-n-puff EOR, the effect of fracture complexity on well productivity was examined by simulation approaches.     

致密油与页岩油的概念与应用

通过国内外大量的文献调研,了解和分析了致密油和页岩油术语的不同含义与应用情况,对比了它们之间的异同点,并提出了应用和完善致密油和页岩油概念的建议。致密油含义有广义与狭义之分;页岩油除用于指油页岩加工的石油外,其含义也有广义和狭义之分。致密油与页岩油异同点表现为3种情况:①致密油与页岩油概念完全不同,属于不同的非常规石油资源类型;②致密油与页岩油含义完全相同,可以互换使用;③致密油与页岩油概念既有关系,也有差别。在应用致密油和页岩油术语时,要遵循"尊重习惯、方便交流"的原则。致密油和页岩油有不同含义,不要只从字面上机械理解,要真正理解它们的实际内涵。对于致密油和页岩油术语使用中遇到的问题,应采取"不断完善,适时修正"的原则,不断完善致密油和页岩油术语的定义,使它们的定义和应用更加科学、规范,同时也要方便、适用和与国际接轨。     

页岩油资源评价关键参数——含油率的校正

页岩油资源评价过程中,常用热解参数S₁（游离烃含量）与氯仿沥青“A”含量反映含油性。但由于实验流程的原因,所测得的S₁存在着轻烃、重烃的损失,氯仿沥青“A”含量存在着轻烃损失。为了更准确地对页岩油资源进行定量评价,通过对松辽盆地北部青山口组泥页岩有机质成烃动力学研究以及对样品抽提前、后的热解参数进行对比,对氯仿沥青“A”含量进行轻烃补偿校正,对S₁进行轻烃、重烃补偿校正,以获得泥页岩总含油率参数。结果表明,松辽盆地北部青山口组泥页岩校正后S₁约为校正前S₁平均值的4.2倍,校正后氯仿沥青“A”含量约为校正前氯仿沥青“A”含量平均值的1.2倍。校正前S₁仅为氯仿沥青“A”含量的0.28倍,校正后S₁与氯仿沥青“A”含量基本相同。可见在页岩油的资源评价过程中,对S₁与氯仿沥青“A”含量的补偿校正是十分必要的。     

就地生成二氧化碳提高采收率研究

对就地生成CO2技术的作用机理进行了研究,在油藏条件下,筛选出生成CO2的体系,同时进行原油膨胀和降粘效果评价;利用微观模型和物理模型研究了其驱油效果。实验结果表明,利用就地生成CO2技术能够生成充足的气体,膨胀原油体积及降低粘度,取得较好的驱油效果。当油藏温度为60℃、压力为10MPa、原油粘度为2010mPa·s时,就地生成的CO2可以使原油体积膨胀25%、粘度降低52.7%,能够提高采收率7.6～14.2个百分点。     

关于致密油气和页岩油气的讨论

在全球范围内,非常规油气勘探开发都正在从幕后步入前台,为了厘清有关概念、明确勘探思路、指导勘探决策,对致密油气和页岩油气等的勘探开发历程和发展前景进行了讨论。结果认为：①目前工业开采中广义的致密储层油气主要包括致密砂岩油气、页岩油气、煤层气,其有效开采依赖于共同的主体技术--水平井和压裂;②美国的非常规油气开发从致密砂岩油气起步向煤层气、页岩气延伸,因气价下跌而促进了页岩油的开采;③近年来页岩气、页岩油成为美国油气产量增速最快的类型,从而使其成为天然气、石油产量增速最快的国家;④据最新资源评价结果测算,页岩油、页岩气分别占世界油、气资源总量的10％、32％;⑤近年世界流行的致密油（ tight liquids）概念,其主体是页岩油,包括天然气液（NGLs,Natural Gas Liquids）和轻质黑油（Light Oil）,生产实践表明,目前仅能开发致密储层油中的相对轻质者,因而可称其为轻质致密油（LTO,Light Tight Oil）。     

页岩油抽出油中氮化物的提取方法研究

在反应温度70℃,反应时间60 min,沉降时间2 h工艺条件下,以TiCl4/CuCl2.2H2O混合物为络合剂,以磷酸/环己烷混合物为萃取剂,研究了提取配方对抚顺页岩油抽出油中氮化物提取效果的影响。结果表明,在m(萃取剂)/m(抽出油)为1.0,m(萃取剂)/m(络合剂)为8.0,m(TiCl4)/m(CuCl2.2H2O)为1.2的最佳条件下,碱性氮和总氮的提取率分别为98.5%,70.5%。     

Pyrolysis characteristics of a North Korean oil shale

Pyrolysis characteristics of a North Korean oil shale and its pyrolysates were investigated in this paper. The pyrolysis experiments were conducted below 600 °C at a heating rate of 10, 15, 20 and 25 °C/min, respectively. The kinetics data were calculated using both integral and differential methods with the assumption of first order kinetics. The results show that the averaged oil content of the North Korean oil shale is about 12.1 wt% and its heat value is 13,400 kJ/kg. The oil yields at different retorting temperatures show that the higher the retorting temperature the greater the oil and retorting gas yields. The optimal retorting temperature for the North Korean oil shale is about 500 oC. The properties of the North Korean shale oil including density, viscosity, flash point and freezing point are found to be relatively low compared with those of shale oil from FuShun, China. The gasoline fraction, diesel fraction and heavy oil fraction account for 11.5 wt%, 41.5 wt% and 47 wt%, respectively. The major pyrolysis gases are CH4(the most abundant), H2, CO2, H2 S, CO, and C2-C5 hydrocarbons. The heat value of retorting gas is more than 900 kJ/mol, and the retorting gas has high sulfur content.     

油页岩流化干馏物料流态化试验

对油页岩流化干馏工艺中页岩粉、页岩灰和半焦三种物料进行了基本物性分析,并对其流态化特性进行了系统的冷模试验研究,结果表明:三种物料具有非球形、宽筛分和非正态分布等特点,其起始流化速度分别为:页岩粉约为0.043 m/s,页岩灰约为0.04 m/s,半焦约为0.032 m/s;带出速度分别为:页岩粉和页岩灰约为0.7 m/s,半焦约为0.55 m/s。三种物料在流化过程中会出现床层的局部颗粒离析分层现象,床层密度沿床层高度有所降低,床层密相密度为350 kg/m~3～800 kg/m~3;三种物料在流化过程中容易形成床层沟流和大颗粒架桥、气体短路,从而导致流化极不均匀,在床层和提升管中均需要较高气速和循环量才能维持操作,与通常的FCC细粉流态化有很大区别。     

页岩油原位成藏过程及油藏特征 ——以松辽盆地古龙页岩油为例

为了搞清古龙页岩油成藏过程及油藏特征,指导古龙页岩油勘探开发,利用大量岩心实验分析数据,分析页岩形成的古沉积环境,通过观察大量扫描电镜照片,深入分析有机质赋存状态.以封闭体系低熟页岩生烃热模拟实验为基础,结合成烃—成岩—成储耦合过程研究,系统分析古龙页岩油成藏过程,从而明确其油藏特征.结果表明:(1)青山口组古沉积环境...     

世界油页岩原位开采技术进展

油页岩原位开采技术不需要进行采矿和建设大型的尾气处理设施,可开发深层、高厚度的油页岩资源,具有产品质量好、采油率高、占地面积少和环保等优点,目前尚处于工业试验阶段。按照油页岩层受热方式的不同,可将油页岩原位开采技术分为传导加热、对流加热、辐射加热3类技术。在此,详细介绍了壳牌石油公司地下转化工艺技术、埃克森美孚公司Electrofrac^TM技术、IEP公司GFC技术等3种传导加热技术,还介绍了太原理工大学的对流加热技术、雪弗龙CRUSH技术等5种对流加热技术,以及2种辐射加热技术,并分析了各类工艺的优缺点。根据我国油页岩资源埋藏深、品位低的特点,应大力开展原位开采技术方面的研究工作,为将来大规模开发油页岩资源提供技术储备。     

抚顺页岩油加氢处理工艺条件的优化

在微型固定床加氢反应装置上,以复合分子筛NiW/HUSY-γ-Al2O3（HUSY质量分数15％）为催化剂,对抚顺页岩油进行加氢处理,考察了工艺条件对加氢处理效果的影响.结果表明,最佳工艺条件为:反应温度400℃,反应压力9.0 MPa,氢油比（体积比）600∶1,液时空速0.5h-1;在此工艺条件下,加氢处理生成油的含硫量由5 571.2 μg/g降至201.1 μg/g,含氮量由12 157.6 μg/g降至1 203.6 μg/g,产品液体收率达到91.2％;与页岩油原料相比,汽油、柴油馏分收率分别提高了7.5,20.4个百分点.     

油页岩热物理性质研究综述

本文回顾了油页岩在加热条件下,油页岩的热解特性、油页岩的导热特性和油页岩的力学特性等基本热物理特性。油页岩热解分为三个阶段:低温水分析出阶段,中温有机质分解阶段和高温结晶水析出阶段;油页岩的导热系数呈现各向异性,平行层理导热系数大于垂直层理的导热系数,且温度对于导热系数的影响较弱;油页岩的抗拉强度、抗压强度、弹性模量和泊松比随温度的升高而减小;油页岩随着温度的升高,蠕变特性更加明显,拉伸破坏往往出现在热解过程中。     

利用微波加热开采地下油页岩的技术

对目前国内外油页岩原位开采技术研究进行的分析表明,油页岩具有导热性差的特点。为了解决传统的热传导开采方法效率低、成本高的问题,提出了一种微波加热开采油页岩的新型技术。利用微波加热方式,电磁能直接作用于介质分子而转换成热能,其透射性能使物料内外介质同时受热,不需要热传导。在方案实施过程中,在油页岩层中钻羽状井并填入吸波介质,可大大改善油页岩的吸波能力,可以以较快的速度使页岩油的升温,并逐渐地将干酪根裂解转化为页岩油气。页岩油气会通过加热产生的裂缝运移到生产井,并被抽排到地面。     

泥页岩中有机质的赋存形态与油气形成

根据不同类型泥页岩镜下微观特征观察,发现泥页岩中的沉积有机质和矿物质主要以"富有机质—矿物聚集体"和"贫有机质—矿物基质体"2种微观组构形态存在。通过泥页岩的生排烃模拟实验研究表明：泥页岩有机质赋存的差异性控制了油气的生成和初次运移过程,由于"富有机质—矿物聚集体"形态组构非均质分布,在不同演化阶段生成、排出及滞留的油气以不同的状态赋存和运移;镜质体反射率（Ro）介于0.6%~1.0%之间,泥页岩层系中滞留的油与富集有机质聚集体呈游离-吸附共轭相态,流动性较差,开采前景较差,Ro介于1.0%~1.3%之间是页岩油开采的有利范围;高演化阶段页岩气资源量的大小受控于泥页岩中富有机质聚集体的含量。基于烃源岩内沉积有机质和无机矿物质微观结构上的非均质性特征,把油气的形成、排出、滞留作为一个统一过程加以认识,将是深入认识页岩油气形成与富集机理的有利手段和重要方法。     

陆相页岩油可动用性微观综合评价

选取目前中国重点开发的准噶尔盆地吉木萨尔凹陷二叠系芦草沟组、鄂尔多斯盆地陇东地区三叠系延长组长73亚段、渤海湾盆地沧东凹陷古近系孔店组孔二段、松辽盆地长岭凹陷白垩系青山口组青一段等4大盆地中高成熟度页岩油作为研究对象,基于储集空间展布多尺度刻画、有效连通性计算、荷电效应可动油评价、改造过程裂缝扩展仿真模拟等技术开发与集成应用,在同一评价技术体系和相同实验测试条件下获取4大盆地页岩油储集层有效性、含油性、原油可动性及可改造性等关键参数,解决常规分析手段分辨率不足、难以定量评价等难题,形成不同类型页岩油资源可动用性评价方法与对比认识。综合实验与对比分析结果显示,国内4大盆地陆相页岩油资源禀赋差异显著,其中准噶尔盆地芦草沟组页岩储集层有效性较好、鄂尔多斯盆地长73亚段可动油占比较高、渤海湾盆地孔二段可改造性最佳,为针对性开发方案与工程技术遴选提供参考和建议。