Role of high-density brines in reservoir development stages:A review

High-density brines have been recognized beneficial for oilfield applications,with various key areas such as drilling,completion and formation evaluation.High-density brines can play a critical role in the development and production of oil and gas reservoirs during the primary,secondary,and tertiary recovery phases.High-density brines can enhance the mobility and recovery of the oil in the reservoir by controlling the density and viscosity.However,a less attention has been given to the application of high-density brine in the area of reservoir development.This review is shedding light on a concise overview of reservoir development stages in association with the recovery mechanisms.In addition,most possible applications of high-density fluids have also been reviewed in the field of the reservoir development.In summary,this review state that high-density brines can be used to stimulate reservoirs by hydraulic fracturing during the primary recovery phase.However,the risk of increased interfacial tension,which relies on the density difference of two fluids,can trap more residual oil relative to conventional water flooding.In addition,high-density brines are effective in decreasing the mobility ratio and facilitating favorable displacement during polymer flooding.However,they can be least effective in alkaline flooding due to the high IFT related to large density differences.Thus,it is suggested to consider the utilization of sustainable high-density brines by taking into account effective factors in petroleum engineering aspects such as stimulation,secondary recovery and polymer flooding.

Research Progress and Present Situation of Tridimensional Reservoir Development

Designing special well patterns, tridimensional reservoir development selects a variety of wells and uses the gravity energy to maximize the hydrocarbon recovery. It's a new development model to implement the oil and gas exploitation economically and efficiently. It is suitable for both huge oiliness altitude reservoirs and large dip-angle sandstone reservoirs, and more for the carbonate reservoirs developed in high-angle fractures, volcanic reservoirs and metamorphic reservoirs.

Numerical Simulation of High Concentration Polymer Flooding in Oilfield Development

The field test of high concentration polymer flooding has the characteristics of high cost, long cycle and irreversibility of the reservoir development process. In order to ensure the best development effect of the development block, this paper simulated and calculated the high concentration polymer flooding development case of the polymer flooding pilot test area through numerical simulation research, and selected the best case through the comparison of various development indicators. The simulation results showed that the larger the polymer dosage and the higher the concentration, the better the oil displacement effect. The best injection method in the construction process was the overall injection of high concentration polymer. The test area should implement high concentration polymer oil displacement as soon as possible. The research results provided theoretical guidance for the future development and management of the pilot area.

Application of Pore Evolution and Fracture Development Coupled Models in the Prediction of Reservoir "Sweet Spots" in Tight Sandstones

The Chang-63 reservoir in the Huaqing area has widely developed tight sandstone ＂thick sand layers, but not reservoirs characterized by rich in oil＂, and it is thus necessary to further study its oil and gas enrichment law. This study builds porosity and fracture development and evolution models in different deposition environments, through core observation, casting thin section, SEM, porosity and permeability analysis, burial history analysis, and ＂four-property-relationships＂ analysis.

鄂尔多斯盆地庆城油田长7页岩油储层多尺度裂缝三维地质建模

页岩油储层普遍发育多尺度天然裂缝,天然裂缝是页岩油储层主要的储集空间和渗流通道,多尺度天然裂缝分布规律制约着页岩油气储层高效开发。本文以鄂尔多斯盆地庆城油田长7页岩油储层为例,结合地表露头、岩心、薄片、测井和地震等资料,在划分多尺度裂缝的基础上,明确了多尺度裂缝的发育特征,形成了多尺度裂缝建模方法,建立了典型区块X井区长71储层多尺度裂缝三维离散网络模型。根据蚂蚁体叠后地震属性明确了大尺度裂缝分布特征,用确定性方法建立了大尺度裂缝地质模型;结合储层地质力学方法和常规测井裂缝解释结果,建立了中、小尺度裂缝发育强度约束体,然后以发育强度约束体为约束,协同中、小尺度裂缝参数,采用随机建模方法分别建立了中、小尺度裂缝地质模型。最终将大、中、小尺度裂缝网络模型融合形成多尺度裂缝网络模型,并建立裂缝等效属性模型。结果表明X井区长71大尺度裂缝发育于该区东北部,中尺度裂缝和小尺度裂缝多发育于该区西部、西南部和东北部大尺度裂缝发育位置。建立的多尺度裂缝模型与单井裂缝发育规律和实际生产动态数据吻合,可为庆城地区X井区页岩油气增储上产提供地质依据。

Current status and construction scheme of smart geothermal field technology

To address the key problems in the application of intelligent technology in geothermal development,smart application scenarios for geothermal development are constructed.The research status and existing challenges of intelligent technology in each scenario are analyzed,and the construction scheme of smart geothermal field system is proposed.The smart geothermal field is an organic integration of geothermal development engineering and advanced technologies such as the artificial intelligence.At present,the technology of smart geothermal field is still in the exploratory stage.It has been tested for application in scenarios such as intelligent characterization of geothermal reservoirs,dynamic intelligent simulation of geothermal reservoirs,intelligent optimization of development schemes and smart management of geothermal development.However,it still faces many problems,including the high computational cost,difficult real-time response,multiple solutions and strong model dependence,difficult real-time optimization of dynamic multi-constraints,and deep integration of multi-source data.The construction scheme of smart geothermal field system is proposed,which consists of modules including the full database,intelligent characterization,intelligent simulation and intelligent optimization control.The connection between modules is established through the data transmission and the model interaction.In the next stage,it is necessary to focus on the basic theories and key technologies in each module of the smart geothermal field system,to accelerate the lifecycle intelligent transformation of the geothermal development and utilization,and to promote the intelligent,stable,long-term,optimal and safe production of geothermal resources.

Progress in China's Unconventional Oil & Gas Exploration and Development and Theoretical Technologies

The new century has witnessed a strategic breakthrough in unconventional oil ＆ gas.Hydrocarbon accumulated in micro-/nano-scale pore throat shale systems has become an important domain that could replace current oil ＆ gas resources.Unconventional oil ＆ gas plays an increasingly important role in our energy demand.Tight gas,CBM,heavy oil and asphaltic sand have served as a key domain of exploration ＆ development,with tight oil becoming a ＇bright spot＇ domain and shale gas becoming a ＇hotspot＇ domain.China has made great breakthroughs in unconventional oil ＆ gas resources,such as tight gas,shale gas,tight oil and CBM,and great progress in oil shale,gas hydrate,heavy oil and oil sand.China has an estimated（223-263）×10~8t of unconventional oil resources and（890-1260）×l0^（12）m^3 of gas resources.China has made a breakthrough for progress in unconventional oil ＆ gas study.New progress achieved in fine-grained sedimentary studies related to continental open lacustrine basin large-scale shallow-water delta sand bodies,lacustrine basin central sandy clastic flow sediments and marine-continental fine-grained sediments provide a theoretical basis for the formation and distribution of basin central reservoir bodies.Great breakthroughs have been made in unconventional reservoir geology in respect of research methodology ＆ technology,multi-scale data merging and physical simulation of formation conditions.Overall characterization of unconventional reservoirs via multi-method and multi-scale becomes increasingly popular and facilitates the rapid development of unconventional oil ＆ gas geological theory,method and technology.The formation of innovative,continuous hydrocarbon accumulation theory,the establishment of the framework of the unconventional oil ＆ gas geological theory system,and the determination of the implications,geological feature,formation mechanism,distribution rule and core technology of unconventional oil＆ gas geological study lays a theoretical foundation for extensive unconventional oil ＆ gas exploration and development.Theories and technologies of unconventional oil ＆ gas exploration and development developed rapidly,including some key evaluation techniques such as ＇sweet spot zone＇ integrated evaluation and a six-property evaluation technique that uses hydrocarbon source,lithology,physical property,brittleness,hydrocarbon potential and stress anisotropy,and some key development ＆engineering technologies including micro-seismic monitoring,horizontal drilling ＆ completion and ＂factory-like＂ operation pattern, ＂man-made reservoir＂ development,which have facilitated the innovative development of unconventional oil ＆ gas.These breakthroughs define a new understanding in four aspects：①theoretical innovation;② key technologies;③ complete market mechanism and national policy support;and ④ well-developed ground infrastructure,which are significant for prolonging the life cycle of petroleum industry,accelerating the upgrade and development of theories and technologies and altering the global traditional energy structure.

Path Choice and Fiscal Policies of Three Gorges Reservoir in Post-Migration Era

The developmental status of the Three Gorges Reservoir in the post-migration era is expounded.Firstly,positioning of ecological reservoir is incompatible with its development;secondly,adopting the market selection and government-directed migration mode;thirdly,tough task in the post-migration era;fourthly,prevention of geological disasters and environmental management.After the analyses,the adoptable approaches for developing the Three Gorges Reservoir are concluded.The approaches cover supporting migrants and trying to stabilize and enrich them;supporting the development of industries around the reservoir;intensifying the construction of ecological environment in the reservoir;and strengthening the support of central fiscal policies.The policies and suggestions on developing the Three Gorges Reservoir from the perspective of fiscal policies are put forward.Firstly,they include the fiscal and tax measures on prompting ecological migration and stabilizing and enriching migrants.The specific measures include the fiscal and tax measures on promoting the employment of migrants;measures on providing social security for migrants;fiscal subsidies and preferential policies and increasing the input on solving the problems left after reconstruction.Secondly,they are the fiscal and tax measures for promoting the industrial development in the reservoir.The specific contents include displaying the functions of industrial fund to optimize the industrial structure of the reservoir;providing preferential policies on taxes to attract capitals and intensifying the strength of local finance.

三峡库区重庆市万州区滑坡发育特征及诱发机理

万州区滑坡在三峡库区具有典型性。本文以三峡库区万州区内滑坡为研究对象,阐明滑坡发育规律、诱发机理。表明:(1)万州区内滑坡以大、中型为主,总体沿水系带状分布,坡度集中在8°~20°,平面形态以箕形、横长形、舌形为主,剖面形态以直线、阶梯、凸形形状为主。(2)多发于雨季,与季节性降雨和库水位调度一致。(3)降雨强度大、持续时间长,稳定性越低;库水位下降速率和下落方式对滑坡稳定性影响较大。

道真县富强水库左岸岩溶发育特征及渗漏研究

富强水库修建于强岩溶发育地区,处于试蓄水阶段。本研究发现左岸有严重渗漏现象,通过大量的工程地质测绘、物探、钻孔、孔内电视、水文地质试验等手段,结合前期勘察及施工成果,研究了库区左岸岩溶发育规律和特征,查明了渗漏原因及范围,通过加深帷幕补强灌浆处理,将渗漏通道进行了封堵,取得明显防渗效果。

济阳坳陷四扣洼陷湖相碳酸盐岩岩溶储层特征及其发育模型

综合利用岩心、薄片、测井、地震等资料,研究四扣洼陷古近系沙河街组四段上亚段湖相碳酸盐岩岩溶作用的类型、特征及其对孔隙分布的控制作用。结果表明:四扣洼陷湖相碳酸盐岩储层经历了同生期、早期近地表、表生期和埋藏期岩溶作用。在礁滩体沉积期,大气淡水选择性溶蚀碳酸盐岩中的不稳定组分形成大量的粒内溶孔和铸模孔;随着湖平面的下降,早期弱固结的礁滩体经历了早成岩近地表岩溶作用,形成大量溶蚀缝、洞,原始结构被破坏,并伴有大量的植物根茎及生物;沙四段沉积期后发育的表生岩溶作用平面影响范围大,岩溶储层主要分布于不整合面之下10 m的深度范围内,单个溶洞由顶部垂直溶蚀带、内部充填角砾岩带和底部弱溶蚀带组成;埋藏岩溶作用主要与有机酸溶蚀碳酸盐岩矿物有关,形成了大量的"蜂窝状"和"针孔状"孔隙。多期溶蚀作用是湖相碳酸盐岩优质储层形成的关键,由岸向湖方向,依次发育表生期岩溶储层—同生期和近地表岩溶储层—复合岩溶储层—埋藏岩溶储层。

三峡库区水样中重金属含量及其对斑马鱼胚胎发育的毒性评价

三峡库区水体污染对库区鱼类生存的影响尚不明晰,因此测试库区水体中污染物含量及其对鱼类早期发育的影响对于库区生态渔业的安全发展具重要意义。研究于三峡库区坝前段典型区域设置3个采样点,用ICP-MS分析了原水中13种重金属的含量,并将斑马鱼胚胎暴露于纤维膜过滤后的水样中,测试其内分泌及发育毒性效应。结果表明,三峡库区水样中13种重金属的浓度均低于地表水环境标准规定的限值,且3号采样点重金属浓度普遍比1号和2号采样点高。经7d暴露后,处理组和对照组中斑马鱼胚胎的孵化率、相对成活率和畸形率(畸形指标包括原肠胚终止、心跳/心率、脊柱畸形、心包囊水肿)均无明显差异;但幼鱼体内生殖相关基因(如α型雌激素受体,雄激素受体和芳香化酶)、甲状腺相关基因(如甲状腺激素受体、甲状腺激素释放激素、Ⅱ型脱碘酶)和神经发育相关基因(如α1微管蛋白、突触蛋白、生长相关蛋白)的转录水平较之对照组(曝气24h的自来水)均显著下降。上述结果表明,三峡库区水体中13种重金属的含量仍处于较低水平,且在此污染水平下不会对斑马鱼胚胎发育过程产生显著影响。此外,污染水体导致的分子水平上的变化是否会引起鱼类生长发育过程中的长期影响尚有待进一步研究。

背斜构造裂缝性碳酸盐岩油藏裂缝网络发育模式——以胜利油区富台油田车古201潜山为例

构造裂缝是裂缝性油藏的主要储集空间和渗流通道,对裂缝网络的描述是裂缝性油藏地质研究的重点和难点。裂缝网络发育受多种因素影响,非均质性极强,结合理论模式,通过野外相似露头,以及胜利油区富台油田车古201潜山油藏的钻井、测井、岩心、分析化验等多种资料、信息,系统研究了大、中、小、微不同尺度裂缝的发育特征及其分布规律,定量确定了不同尺度裂缝的关键特征参数,在此基础上针对背斜潜山不同构造部位(背斜轴部、翼部、倾末端),建立了背斜构造裂缝性油藏裂缝网络发育模式,为准确把握裂缝性油藏裂缝分布规律及高效部署开发井提供地质保障和依据。

桩海地区下古生界潜山储层发育规律与发育模式

桩海地区位于济阳坳陷渤海湾南部极浅海地区。下古生界包括寒武系和下、中奥陶统,主要由海相碳酸盐岩构成。古潜山主要发育风化壳岩溶带储层和内幕储层。下古生界碳酸盐岩裂缝-溶蚀型储集层的发育特征以有无上古覆盖是岩溶发育的前提;古地貌、古水系控制岩溶发育强度。其发育规律为:岩溶作用是下古生界储集层发育的基础;岩性和断裂作用决定内幕储层的形成与发育。主要以岩溶作用产生的背景与条件、发展或消亡过程为主线,辅以断裂与裂缝对储层的改造作用,分2个层次建立了下古生界碳酸盐岩储层的发育模式。经钻采实践检验,储层发育规律与建立的储层发育模式均得到证实。

适用于开发后期的CYL-1型液固两相防砂材料研制

液固两相防砂剂CYL 1为可固化的悬浮液 ,固相为密度 1.15～ 1.30 g/cm3 、粒径 0 .2～ 0 .5mm(适用于弧东油田 )的矿渣颗粒 ,液相为加有固化剂、偶联剂 (KH 5 5 0 )及增孔剂 (清水 ) ,密度 1.10～ 1.2 0 g/cm3 的改性脲醛树脂 (UF K)溶液。该防砂剂可满足油藏开发后期分层防砂施工的要求。报道了主要组分 (脲醛树脂、偶联剂 )品种和矿渣颗粒粒度的选择。基于各组分用量和液固比的优选 ,根据固结样抗折强度和渗透率两项性能 ,确定了基本配方 :液固体积比 1∶0 .6～ 0 .8,UF K、固化剂、偶联剂、增孔剂质量比 10 0∶0 .7∶1.0∶5 0。基本配方悬浮液粘度在2 0 0mPa·s左右 ,在 6 0℃能保持稳定 2h ,固化时间 >1h ,固结样抗折强度 >3.0MPa ,渗透率 2 .6 μm2 ,耐 6 0℃的清水、污水、卤水、柴油和原油 ,在 6 0℃的 10 %盐酸和 5 %NaOH溶液中破坏。用基本配方液相固结孤东地层砂 ,在5 0℃放置 2d后 ,抗折强度 3.1MPa ,渗透率 2 .1μm2 。

油气储层随机模拟方法综述

油气储层随机模拟方法是近年来新发展起来的一门油气预测技术,它在综合了地质、地球物理信息的基础上充分利用了已知点的储层信息,根据所要预测的储层属性的来选择不同的随机模型,其最终模拟结果可以有任意多个供油藏描述选择.文章简要介绍了目前比较常用的储层属性随机模拟方法、原理以及各方法的优缺点、适用情况、今后的发展趋势.

三峡库区后移民时代发展的路径选择和财政政策

首先,阐述了三峡库区后移民时代发展现状:一是生态库区的定位与发展存在矛盾;二是采取市场选择、政府引导的开发性移民模式;三是移民后期扶持任务艰巨;四是地质灾害的防治与环境治理。其次,概括和梳理得到三峡库区后移民时代发展可采取的路径:一是扶持移民安稳致富;二是支持库区产业发展;三是加强库区生态环境建设;四是加大中央财政政策的支持。最后,从财政政策视角提出了三峡库区后移民时代发展的政策建议:一是促进生态移民搬迁及移民安稳致富的财税政策措施,具体包括促进移民就业的财税政策措施、为移民提供社会保障的财税政策措施、财政补贴和税收优惠、追加后续投资解决迁建遗留的问题四大措施;二是促进库区产业发展的财税政策措施,具体包括发挥产业基金的产业造血功能与优化库区产业结构、给予特殊的税收优惠政策与引导资金投向三峡库区、增强地方财力的财税政策措施三大措施。

三峡库区农村工业发展模式研究

农民、农村、农业这“三农”问题是目前中国社会经济生活中面临的重大问题 ,而解决这一问题的关键是提高农村地区整体经济发展水平 ,促进农村劳动力向非农产业转移。三峡库区主体地处我国经济落后的西部地区 ,广大农村耕地资源有限 ,人口密度很大 ,人地关系十分紧张 ,致使库区生态环境受到较大的破坏 ,阻碍了农村经济的发展 ,并对三峡工程构成极大威胁。在库区发展农村工业 ,推进农村工业化的进程 ,可以加快农村经济发展、促进农村劳动力向工业转移 ,缓解库区日益紧张的人地关系。本文在对库区 1 9个区县农村工业发展实地调查的基础上 ,通过对三峡库区农村工业发展状况和空间分布特点的分析 ,运用一般类型分析的方法将库区农村工业分为城郊型农村工业区 ,远郊型农村工业区 ,远离中心城市的平原型农村工业区 ,山区型农村工业区四种类型 ,并针对每种类型区提出具体的发展模式。这不但对解决三峡库区农村工业发展问题具有较强的实践意义 ,而且对我国其他经济不发达地区的农村工业发展有一定的借鉴意义。

吐鲁番坳陷中下侏罗统层序地层格架内有利储集砂体分布规律

利用层序地层学理论,在吐鲁番坳陷中下侏罗统确定3类层序界面识别标志,划分出5个三级层序,10个四级层序,建立吐鲁番坳陷中下侏罗统的层序地层格架。研究结果表明:吐鲁番坳陷侏罗纪时期南部物源发育,中下侏罗统地层具有南薄北厚的特点;其层序形成具缓坡背景浅水湖盆和具沉积坡折背景浅水湖盆2种发育模式;吐鲁番坳陷中下侏罗统共发育5套主要的有利储集砂体,其中三间房组下部沉积的辫状河—曲流河三角洲中厚层-厚层砂岩层是研究区最有利储集砂体。

孤东油田化学防砂

孤东油田砂岩油藏胶结疏松 ,油水井出砂严重 ,自上世纪 80年代以来 ,开发并应用了适合不同开发阶段的一系列化学防砂方法 ,即酚醛溶液地下合成防砂、脲酚树脂溶液防砂、干水泥砂防砂、酚醛树脂涂敷砂防砂、低温涂敷砂防砂、轻质涂敷砂防砂、复合砂防砂、固结砂防砂、LS 1固液两相材料防砂等 9种方法 ,介绍了每一种防砂方法的原理、选井条件、工艺技术特点。