Prediction of Sedimentary Microfacies Distribution by Coupling Stochastic Modeling Method in Oil and Gas Energy Resource Exploitation

In view of the problem that a single modeling method cannot predict the distribution of microfacies, a new idea of coupling modeling method to comprehensively predict the distribution of sedimentary microfacies was proposed, breaking the tradition that different sedimentary microfacies used the same modeling method in the past. Because different sedimentary microfacies have different distribution characteristics and geometric shapes, it is more accurate to select different simulation methods for prediction. In this paper, the coupling modeling method was to establish the distribution of sedimentary microfacies with simple geometry through the point indicating process simulation, and then predict the microfacies with complex spatial distribution through the sequential indicator simulation method. Taking the DC block of Bohai basin as an example, a high-precision reservoir sedimentary microfacies model was established by the above coupling modeling method, and the model verification results showed that the sedimentary microfacies model had a high consistency with the underground. The coupling microfacies modeling method had higher accuracy and reliability than the traditional modeling method, which provided a new idea for the prediction of sedimentary microfacies.

Integrated Reservoir Prediction and Oil-Gas Evaluation in the Maoshan Area

The Maoshan area is an area with well-developed igneous rocks and complex structures. The thickness of the reservoirs is generally small. The study of the reservoirs is based on seismic data, logging data and geological data. Using techniques and software such as Voxelgeo, BCI, RM, DFM and AP, the authors have made a comprehensive analysis of the lateral variation of reservoir parameters in the Upper Shazu bed of the third member of the Palaeogene Funing Formation, and compiled the thickness map of the Shazu bed. Also, with the data from ANN, BCI and the abstracting method for seismic characteristic parameters in combination with the structural factors, the authors have tried the multi-parameter and multi-method prediction of petroleum, delineated the potential oil and gas areas and proposed two well sites. The prediction of oil and gas for Well JB2 turns out to be quite successful.

Evaluation of reservoir environment by chemical properties of reservoir water‒A case study of Chang 6 reservoir in Ansai oilfield,Ordos Basin,China

The Ordos Basin is the largest continental multi-energy mineral basin in China,which is rich in coal,oil and gas,and uranium resources.The exploitation of mineral resources is closely related to reservoir water.The chemical properties of reservoir water are very important for reservoir evaluation and are significant indicators of the sealing of reservoir oil and gas resources.Therefore,the caprock of the Chang 6 reservoir in the Yanchang Formation was evaluated.The authors tested and analyzed the chemical characteristics of water samples selected from 30 wells in the Chang 6 reservoir of Ansai Oilfield in the Ordos Basin.The results show that the Chang 6 reservoir water in Ansai Oilfield is dominated by calcium-chloride water type with a sodium chloride coefficient of generally less than 0.5.The chloride magnesium coefficients are between 33.7 and 925.5,most of which are greater than 200.The desulfurization coefficients range from 0.21 to 13.4,with an average of 2.227.The carbonate balance coefficients are mainly concentrated below 0.01,with an average of 0.008.The calcium and magnesium coefficients are between 0.08 and 0.003,with an average of 0.01.Combined with the characteristics of the four-corner layout of the reservoir water,the above results show that the graphics are basically consistent.The study indicates that the Chang 6 reservoir in Ansai Oilfield in the Ordos Basin is a favorable block for oil and gas storage with good sealing properties,great preservation conditions of oil and gas,and high pore connectivity.

An improved oil recovery prediction method for volatile oil reservoirs

To describe the complex phase transformation in the process of depletion exploitation of volatile oil reservoir,four fluid phases are defined,and production and remaining volume of these phases are calculated based on the principle of surface volume balance,then the recovery prediction method of volatile oil reservoir considering the influence of condensate content in released solution gas and the correction method of multiple degassing experiments data are established.Taking three typical kinds of crude oil(black oil,medium-weak volatile oil,strong volatile oil)as examples,the new improved method is used to simulate constant volume depletion experiments based on the corrected data of multiple degassing experiment to verify the reliability of the modified method.By using"experimental data and traditional method","corrected data and traditional method"and"corrected data and modified method",recovery factors of these three typical kinds of oil are calculated respectively.The source of parameters and the calculation methods have little effect on the recovery of typical black oil.However,with the increase of crude oil volatility,the oil recovery will be seriously underestimated by using experimental data or traditional method.The combination of"corrected data and modified method"considers the influence of condensate in gas phase in both experimental parameters and calculation method,and has good applicability to typical black oil and volatile oil.The strong shrinkage of volatile oil makes more"liquid oil"convert to"gaseous oil",so volatile oil reservoir can reach very high oil recovery by depletion drive.

Geological characteristics and co-exploration and co-production methods of Upper Permian Longtan coal measure gas in Yangmeishu Syncline, Western Guizhou Province, China

Coal measure gas(also known as coal-bearing unconventional gas)is the key field and development direction of unconventional natural gas in recent years.The exploration and evaluation of coal measure gas(coalbed methane,coal shale gas and coal measure tight sandstone gas)from single coalbed methane has greatly expanded the field and space of resource evaluation,which is of positive significance for realizing the comprehensive utilization of coal resources,maximizing the benefits and promoting the innovation of oil and gas geological theory and technological advances in exploration and development.For the first time,in Yangmeishu Syncline of Western Guizhou Province,the public welfare coalbed methane geological survey project of China Geological Survey has been carried out a systematic geological survey of coal measure gas for the Upper Permian Longtan Formation,identified the geological conditions of coal measure gas and found high quality resources.The total geological resource quantity of coalbed methane and coal shale gas is 51.423×109 m3 and the geological resource abundance is up to 566×106 m3/km2.In this area,the coal measures are characterized by many layers of minable coal seams,large total thickness,thin to the medium thickness of the single layer,good gas-bearing property of coal seams and coal measure mudstone and sandstone,good reservoir physical property and high-pressure coefficient.According to the principle of combination of high quality and similarity of key parameters of the coal reservoir,the most favorable intervals are No.5-2,No.7 and No.13-2 coal seam in Well YMC1.And the pilot tests are carried out on coal seams and roof silty mudstone,such as staged perforation,increasing hydraulic fracturing scale and"three gas"production.The high and stable industrial gas flow with a daily gas output of more than 4000 m3 has been obtained,which has realized the breakthrough in the geological survey of coal measure gas in Southwest China.Based on the above investigation results,the geological characteristics of coal measure gas in the multi-thin-coal-seam-developed area and the coexploration and co-production methods,such as the optimization method of favorable intervals,the highefficiency fracturing and reservoir reconstruction method of coal measures,and the"three gas"drainage and production system,are systematically summarized in this paper.It will provide a reference for efficient exploration and development of coal measure gas in similar geological conditions in China.

A novel type curve for estimating oil recovery factor of gas flooding

A novel type curve is presented for oil recovery factor prediction suitable for gas flooding by innovatively introducing the equivalent water-gas cut to replace the water cut,comprehensively considering the impact of three-phase flow(oil,gas,water),and deriving the theoretical equations of gas flooding type curve based on Tong’s type curve.The equivalent water-gas cut is the ratio of the cumulative underground volume of gas and water production to the total underground volume of produced fluids.Field production data and the numerical simulation results are used to demonstrate the feasibility of the new type curve and verify the accuracy of the prediction results with field cases.The new type curve is suitable for oil recovery factor prediction of both water flooding and gas flooding.When a reservoir has no gas injected or produced,the gas phase can be ignored and only the oil and water phases need to be considered,in this case,this gas flooding type curve returns to the Tong’s type curve,which can evaluate the oil recovery factor of water flooding.For reservoirs with equivalent water-gas cuts of 60%-80%,the regression method of the new type curve works well in predicting the oil recovery factor.For reservoirs with equivalent water-gas cuts higher than 80%,both the regression and assignment methods of the new type curve can accurately predict the oil recovery factor of gas flooding.

鄂尔多斯盆地马岭—乔川地区长6油层组油藏分布特征及控制因素

基于岩心观察、测井解释及开采数据分析,结合流体包裹体等测试,对马岭—乔川地区长6油层组的油藏分布特征及控制因素开展研究。研究结果表明,研究区油藏纵向上主要分布在长63油层段,长62、长61油层段含油性显著变差;平面上,长63油层段以L125,B452和L411井区为中心,油藏团块状分布,呈两条带沿北西南东向延伸,油层厚度主要在5~20 m之间,长62、长61油层呈孤立土豆疙瘩状分布,分布规模小。长6油层组油藏以岩性油藏为主,包裹体均一温度集中在70~90℃,荧光以黄褐色为主,结合区域埋藏史分析显示该区油藏充注为晚侏罗世和中-晚白垩世,表现为早期充注。长6油层组烃源岩厚度、距离,砂体砂质碎屑流砂体性质、物性和叠置类型是其形成油气藏的重要影响因素;长63油层段相比长62和长61油层段具有更靠近烃源岩,砂质碎屑流成因砂体分布广、孔渗条件好、叠置厚层砂体类型发育等优势。研究区最为有利油藏的勘探目标为长63油层段Y470,L374,B452等井区附近,有利勘探区面积达到517.28 km 2。

北部湾盆地涠西南凹陷WH油田沉积相研究及甜点预测

WH油田主要含油层段为流沙港组流一段,储层厚度和岩性变化快,砂体分布及连通性复杂。为厘清流一段储层分布和甜点区域,提高油田开发效益。通过测井、岩心分析和地震资料分析认为,流一段储层为缓坡陡倾型扇三角洲前缘亚相沉积,识别出水下分流河道、河口坝、席状砂、前缘滑塌、水下碎屑流、分流间湾6种沉积微相。通过物源分析、单井与连井微相、砂体追踪和储层反演预测,厘清了井间砂体连通性,精细刻画了储层展布特征,并建立了油田沉积模式和沉积演化规律。纵向上,流一段早期为扇三角洲平原和三角洲前缘亚相,逐渐演化为滨浅湖亚相;晚期演化为席状砂为主的扇三角洲前缘—前扇三角洲亚相。平面上,在5井区发育扇三角洲平原亚相沉积;3井区与6井区发育前缘水下分流河道沉积;2井区为前缘远砂坝—席状砂和前三角洲泥沉积;提出无井控的中部砂体为甜点区域。

Data driven prediction of oil reservoir fluid properties

Accuracy of the fluid property data plays an absolutely pivotal role in the reservoir computational processes.Reliable data can be obtained through various experimental methods,but these methods are very expensive and time consuming.Alternative methods are numerical models.These methods used measured experimental data to develop a representative model for predicting desired parameters.In this study,to predict saturation pressure,oil formation volume factor,and solution gas oil ratio,several Artificial Intelligent(AI)models were developed.582 reported data sets were used as data bank that covers a wide range of fluid properties.Accuracy and reliability of the model was examined by some statistical parameters such as correlation coefficient(R2),average absolute relative deviation(AARD),and root mean square error(RMSE).The results illustrated good accordance between predicted data and target values.The model was also compared with previous works and developed empirical correlations which indicated that it is more reliable than all compared models and correlations.At the end,relevancy factor was calculated for each input parameters to illustrate the impact of different parameters on the predicted values.Relevancy factor showed that in these models,solution gas oil ratio has greatest impact on both saturation pressure and oil formation volume factor.In the other hand,saturation pressure has greatest effect on solution gas oil ratio.

四川盆地下侏罗统大安寨段页岩油气地质特征及勘探有利区优选

四川盆地下侏罗统大安寨段是页岩油气(致密油气)分布的主要层系之一,但由于钻探、测试效果均较差,急需开展有利层段地质特征和勘探有利区优选等研究工作。为此,利用野外露头、岩心、测录井及地球物理等资料研究了大安寨段页岩油气地质特征,分析了页岩油气富集的主控因素,并优选了勘探有利区。研究结果表明:①大安寨段为一套介壳石灰岩与黑色页岩的混积地层,页岩矿物类型以黏土为主,其次为石英、方解石,少量长石、黄铁矿,脆性矿物含量中等;②孔隙类型以无机孔隙为主,含少量有机孔,发育介壳壳缘缝、节理缝等多尺度裂缝,物性随介壳含量的增加而降低;③页岩有机质丰度为中等—好,TOC平均值为1.34%,有机质类型以混合型为主,少量腐泥型和腐殖型,R_(o)平均值为1.11%,热演化程度南低北高,整体处于成熟—高成熟阶段,含油性中等,氯仿沥青“A”含量平均为0.26%;④热解游离烃S1值平均为1.27 mg/g,OSI平均值为84.35 mg/g,页岩油气富集的烃源下限是TOC>1.5%,R_(o)>0.9%,纵向上排烃效率较低,含油指标较高段(OSI>100 mg/g)主要分布于厚层页岩中部;⑤可动油饱和度普遍小于20%,受纹理缝和页理缝影响,石灰岩—页岩互层型、页岩夹石灰岩型样品的油可动性好于石灰岩和页岩。结论认为,大安寨段页岩层系具有较好的页岩油气勘探开发潜力,高生烃品质、多尺度裂缝以及高地层压力是盆地页岩油气富集高产的关键因素,有利油气勘探区主要分布于川中地区三台—仪陇以及南充一带。

断层输导差异性定量评价及其在致密油气藏勘探中的应用

沟通烃源岩与储层的通源断层在活动期会产生诱导裂缝、碎裂岩或断层岩,对油气运移起输导作用。受断层活动强度、两侧岩性、断层岩泥质含量等因素的影响,断层不同部位(断片区)对流体的输导能力存在差异。断层输导差异性定量评价有助于断控致密油气成藏有利区预测。基于断层生长指数、断生裂缝系数和岩石破裂压力等参数,提出断层输导指数计算方法,明确了断控致密油气成藏机理与成藏模式。根据烃源岩厚度、成熟度及类型等参数,计算烃源岩系数,综合分析济阳坳陷渤南洼陷渤深4断层各断片区的输导指数、烃源岩系数、源储压差、有利储集相带等,建立断控致密油气成藏有利区分类标准,预测的成藏有利区得到了勘探实践证实。结果表明:按断片区计算断层输导指数,可以定量评价断层输导能力的差异性;高源储压差、通源断层差异输导和断层岩侧向封堵是断控致密油气成藏的主控因素。

断裂输导形成上覆油气藏有利部位预测方法及其应用

为明确含油气盆地断裂输导形成上覆油气藏的分布规律,在断裂输导形成上覆油气藏所需条件研究的基础上,通过确定下伏油气藏分布区、下伏油气藏断盖配置不封闭区、上覆油气藏断盖配置封闭区和油气沿断裂运移有利部位,四者叠合建立了一套断裂输导形成上覆油气藏有利部位的预测方法,并将其应用于海拉尔盆地贝尔凹陷霍多莫尔地区断裂输导南屯组油气至大磨拐河组形成油气藏有利部位的预测中。结果表明:贝尔凹陷霍多莫尔断裂输导南屯组油气藏油气至大磨拐河组中形成油气藏的有利部位主要分布在霍多莫尔鼻状构造核部的3个局部区内,有利于断裂输导南屯组油气藏油气至大磨拐河组中形成上覆油气藏,与目前贝尔凹陷霍多莫尔地区大磨拐河组已发现油气分布相吻合,表明该方法用于预测断裂输导形成上覆油气藏有利部位是可行的。研究方法对含油气盆地断裂输导形成的上覆油气藏勘探开发具有重要的指导意义。

基于结构方程的非常规有利区优选方法与体系研究

针对中国非常规油气田勘探开发目前尚未建立完善的目标区优化体系的现状,在现有非常规油气田开发评价理论的基础上,借鉴国外非常规油气田开发评价体系的经验和合理方法,结合鄂尔多斯盆地非常规油气田地质特征,选取实际区块页岩资源丰度、页岩有效厚度、成熟度等10种影响因素,建立了结构方程模型与模糊积分评价相结合的优化体系,开展非常规油气田不同指标体系选区优化研究,应用效果较好。研究表明,基于结构方程模型评价方法能够客观、全面地识别目标区域优化系统的影响因素,并计算出各影响因素的权重,使评价结果更加客观准确,为决策者提供一定的理论依据。研究成果对非常规油气藏的勘探、井位部署及提高采收率具有一定借鉴意义。

饶阳凹陷赵皇庄-肃宁构造带奥陶系潜山勘探潜力简析

饶阳凹陷是冀中坳陷发现潜山最多、潜山油藏规模最大的富油凹陷,尽管经过多年的勘探,饶阳凹陷仍具有较大的勘探潜力。饶阳凹陷中部的赵皇庄-肃宁构造带潜山虽然勘探程度较高,但奥陶系潜山一直没有突破,具有较大的勘探潜力。由于该构造带的断裂系统复杂、钻井出露的潜山层位多,影响了奥陶系潜山地层的准确落实;而且钻入第三系沙三段地层的井较少,也给奥陶系潜山油源分析带来一定困难。为此采用了加强潜山层位对比及区域分布特征研究,推算该区奥陶系地层的厚度;以已知井进山层位为依据,重新精细梳理断层,加强潜山断裂结构研究,确定断槽内奥陶系层位的存在;加强下第三系沙三段暗色泥岩分析,寻找奥陶系潜山油气运移通道等方法。通过综合研究分析,构建该区奥陶系潜山的油藏模式,提出奥陶系潜山有利目标,明确了该区奥陶系潜山具有较大的勘探前景,从而为华北油田的增储上产奠定了坚实基础。

准噶尔盆地深部致密油藏形成条件与分布预测——以玛湖凹陷西斜坡风城组致密油为例

以准噶尔盆地玛湖凹陷西斜坡风城组致密油为研究对象,通过对烃源岩和储层系统分析,阐明深部致密油的形成条件,并预测致密油有利勘探区带。研究结果表明准噶尔盆地玛湖凹陷西斜坡深部具有很好的致密油形成条件:TOC分布在1.1%~2.0%,Ro分布在1.0%~1.6%,有效烃源岩厚度最大可达200 m;目前发现的油气主要分布在生烃强度大于250×104t/km2范围。储层控制了致密油的成藏门限,其储层有效孔隙度下限为2%;储层孔隙度和厚度控制了致密油藏的含油气性;深部储层范围(孔隙度≤10%)决定了致密油藏的边界。应用功能要素组合控藏模式"T-LDPS"对玛湖凹陷西斜坡深部有利勘探区带进行了预测,显示潜在勘探区域主要分布在风南7井区—夏72井区及其以南周边、百泉1井区以南和风城011井区以东。

克拉玛依中拐地区三工河组和八道湾组沉积相新认识

克拉玛依油田中拐地区侏罗系为陡坡沉积体系,具有水力梯度大、相带变化快、厚度变化大的特点。根据中拐地区侏罗系岩相、测井相和地震相标志,以岩心微相标定测井相,以测井相标定地震相。综合研究分析表明,中拐地区下侏罗统三工河组、八道湾组以发育中小型冲积扇、辫状河及辫状河三角洲沉积为主,划分为5个相、16个亚相4、3个微相,并确定了最有利的储集层位及有利相带。

基于岩石物理的致密砂岩油藏叠前优势储层预测——以渤海湾盆地南堡凹陷4号构造东营组二段为例

针对致密砂岩油层与围岩波阻抗叠置严重、油层与围岩区分难度大等问题,应用岩石物理建模与分析、地震正演模拟、叠前弹性参数反演、贝叶斯岩相判别等技术对渤海湾盆地南堡凹陷4号构造东营组二段致密砂岩油藏优势储层进行预测。在测井资料预处理基础上,依据Biot-Gassmann理论,对Xu-White模型所需岩石物理参数进行计算,并正演估算弹性参数。采用Biot-Gassmann方程与Brie经验公式进行流体替换,建立岩石物理解释量版,进而优选出致密砂岩储层敏感弹性参数;同时根据不同地质模型与AVO正演模拟,确定储层预测极限厚度、有效目标和反演方法。最后利用贝叶斯判别方法计算叠前弹性参数反演成果的岩相类型概率分布,对有利孔隙砂岩分布进行预测。结果表明:油藏状态下纵横波速度比和纵波阻抗为最敏感的岩石弹性参数,对砂岩、泥岩具有区分能力;储层预测的有效目标是地震可识别层段内具有厚度比例优势的有利孔隙砂岩,叠前弹性参数反演和岩性与流体概率分析是解决研究区优势储层预测的有效方法;应用该方法预测的有利孔隙砂岩分布与实钻井吻合度高,储层分布规律与研究区地质规律一致,提高了油层识别能力及预测精度。

中国典型火山岩油气藏地球物理特征及有利区带预测

对松辽盆地、渤海湾盆地和准噶尔盆地中不同构造背景和岩性类型的火山岩油气藏地球物理特征的综合分析表明,松辽盆地的酸性火山岩气藏具有重力负异常、弱磁异常、次高电阻异常和地震杂乱低频强反射的特征;渤海湾盆地的基性火山岩油藏具有重力正异常、强磁异常和地震杂乱低频不连续反射的特征;准噶尔盆地的中酸性火山岩油藏具有过渡型重磁异常、高电阻异常和地震杂乱低频弱反射的特征。根据近烃源岩或沟通烃源岩的航磁异常梯度带是火山岩油气富集区带的地质认识,综合预测了长深1井区、枣北地区和石西陆东地区火山岩储层发育的有利区带。总结了火山岩油气综合勘探的基本思路和对策。

松辽盆地敖古拉地区萨零组油藏特征及圈闭预测

松辽盆地敖古拉地区萨零油层组油气产量高,但油水关系复杂、油气富集规律认识不清。为了认清油藏特征,在井震资料结合的基础上,应用油藏解剖方法对油藏进行精细分析。研究认为:萨零组发育断层—岩性、岩性两种油藏类型,断层—岩性油藏即砂体的上倾方向被断层切割并遮挡而形成的油藏,岩性油藏即砂体的上倾方向尖灭而形成的油藏,剩余油气资源分布在断层—岩性、岩性油藏中,油藏高点处油气更富集;断层—岩性油藏沿敖古拉等5条断裂发育,分布在中部、西南部及东南部,岩性油藏受河口坝砂体控制,分布在北部和南部。利用砂体预测图与砂体顶面构造图叠合来识别断层—岩性、岩性油藏目标的方法,预测了30个有利勘探目标。

靖边东南部前侏罗纪古地貌特征及其对延9油藏的控制作用

靖边东南部前侏罗纪古地貌一直以来缺乏整体性和系统性的研究。运用补偿厚度印模法建立了研究区前侏罗纪古地貌图,并结合构造、沉积相研究分析了古地貌对延9油藏的控制作用。研究表明,古地貌景观控制着延9沉积相展布及压实披盖构造的形成,古斜坡部位易形成良好的构造与沉积相的有机配置,控制着延9油藏的分布。研究古地貌对延9油藏的控制作用对研究区延9油藏建产、有利区预测有指导意义。