Characterization of Architectural Elements of Ordovician Fractured-cavernous Carbonate Reservoirs,Tahe Oilfield,China

A new method for characterizing architectural elements of fractured-cavernous carbonate reservoirs was proposed, with application to an Ordovician reservoir in the Tahe Oilfield, Tarim basin. The new method integrates observations from outcrop analogs and concepts from modern karst theory for the mapping and modeling of fractured-cavernous reservoirs. In this paper, fractured-cavernous reservoirs were divided into 4 architectural element types—underground river caverns, sinkholes, discrete internal caverns, and faults. Architectural elements of the Ordovician reservoir in Tahe oilfield were identified and characterized by integrating well logs and seismic data. A new method constrained by faults, karst zones, and seismic acoustic impedance data, was introduced to build a 3D model of architectural elements of fractured-cavernous reservoir in the S48 unit of Tahe Oilfield. A porosity model was then derived from the architectural element model using facies-constrained method. The research provides a work-flow for the characterization of fracturedcavernous reservoirs and determining optimal methods for maximizing oil recovery in the study area or in similar areas.     

Strata反演技术在柳屯洼陷沙三2-3亚段储层描述中的应用

地震波阻抗反演技术已日益成为油气藏勘探、开发中储集层横向预测的重要手段。柳屯洼陷沙三^2-3亚段同时发育浊积砂体和厚层盐岩,横向相变剧烈。笔者论述了Strata反演的原理及其在该区的应用,在大量统计的基础上建立了不同岩性与波阻抗之间的解释标准。通过对反演剖面的解释,明确了深水浊积扇向盐湖相的渐变关系,做出了各体系域的砂体等厚图,描述了储层的空间展布特征。     

马朗凹陷牛东地区卡拉岗组火山岩储层建模研究

火山岩储层比碎屑岩具有更强的非均质性,储层的地质建模工作变得非常复杂。针对马朗凹陷牛东地区卡拉岗组玄武岩和火山岩的储层地质特征,运用petrel建模软件对储层进行三维地质建模。首先利用钻井、测井、录井、地震、岩心分析化验等资料完成了地层对比,建立地层格架。在此基础上,综合测井与地震资料,建立该地区的构造模型、岩相模型和含油饱和度模型,应用蚂蚁体示踪的方法建立了裂缝分布模型。建模结果检验与实际情况相吻合,为油藏开发方案控制提供了主要依据。     

Jason软件在霸县凹陷文安城东地区储层预测中的应用

研究采用Jason地震反演软件对地质条件复杂的霸县凹陷文安城东地区进行了储层横向分布预测,利用地质、钻井、测井和地震等综合资料进行地震反演技术,对储层进行预测。采用约束稀疏脉冲反演方法,把叠后的地震反射振幅数据变换为地层波阻抗数据,然后利用反演的波阻抗数据,估算出砂岩厚度和砂岩储层物性参数,做出砂体厚度图,对该地区的砂体展布进行分析。结果表明砂体总体走向与波阻抗的高值区较一致,构造的基本特征及形态与地质认识基本一致。     

基于时间卷积网络的地震波阻抗反演

近些年来,深度学习网络的兴起极大地推动了人工智能技术在地震数据处理、反演以及解译等领域的应用.地震波阻抗反演是石油地震勘探领域的一项关键技术,其反演精度在圈定油气储层构造中起到非常重要的作用.提出了一种基于数据驱动时间卷积网络（temporal convolution network,TCN）模型的地震波阻抗反演方法,旨在无需建立初始反演模型,直接利用工区的少量测井标签数据,以地震振幅数据为输入,将波阻抗反演转化为时间序列建模任务,最终输出地下模型的阻抗信息.采用Marmousi2数据集对基于TCN的波阻抗反演模型进行训练、验证和测试,结果显示,在测试集上该模型预测结果的皮尔逊系数和决定系数分别达到97.92%和95.95%,并对远离训练区域的波阻抗信息预测有着良好的泛化性,且在预测时间和预测精度等方面都要明显优于前人的相关研究工作.上述结果表明,TCN时间序列深度学习模型在复杂地层波阻抗反演中具有一定优越性和应用前景,为地震波阻抗反演提供了新思路.      

地震波阻抗反演方法之改进与三阶段、九步骤反演方法的初步实践

地震波阻抗反演在储层预测中发挥了重要作用,它是确保地震数据、测井曲线、速度和地质信息正确综合的首要技术。地震反演的方法很多,对当前石油工业界常用的5种地震波阻抗反演方法的技术关键、适用性进行了分析和对比。由于受地震资料、地质条件和勘探开发程度的制约,现有波阻抗反演方法各具适应性,并不能很好地解决油田储层地震预测问题。为此,提出了一种新的工作思路--三阶段、九步骤反演方法。 应用该方法在松辽盆地GLB地区PTH油层的勘探部署和储量评价中取得较好效果,可预测1~2 m薄储层,对于国内类似地质条件的薄储层预测具有一定的借鉴意义。     

万昌地区永二段水下滑塌扇内上倾尖灭砂体识别

上倾尖灭型油气藏是岩性油气藏的基本类型之一.对上倾尖灭砂体的识别是岩性油气藏勘探的任务之一.在对比单一利用地震资料、地震属性和波阻抗反演等方法进行砂体识别的优缺点后, 提出运用波阻抗和瞬时相位相叠合的新方法对砂体进行识别.运用此方法, 对万昌地区水下滑塌扇内部上倾尖灭砂体进行了精细解释和分析.得出以下结论: (1)通过钻井岩心识别沉积相类型, 结合均方根振幅属性和同沉积断层分布情况, 可以准确地确定伊通盆地万昌地区永二段水下滑塌扇的分布范围; (2)用波阻抗和瞬时相位属性联合的方法对水下滑塌扇内部上倾尖灭砂体进行识别取得了较好的效果, 万昌地区WC1井附近水下滑塌扇内至少有两期最具油气勘探价值的上倾尖灭砂体.      

Exploring the effects of data quality,data worth,and redundancy of CO2 gas pressure and saturation data on reservoir characterization through PEST inversion

This study examined the impacts of reservoir properties on carbon dioxide (CO₂) migration after subsurface injection and evaluated the possibility of characterizing reservoir properties using CO₂ monitoring data such as spatial–temporal distributions of gas pressure, which can be reasonably monitored in practice. The injection reservoir was assumed to be located 1,400–1,500 m below the ground surface such that CO₂ remained in the supercritical state. The reservoir was assumed to contain layers with alternating conductive and resistive properties, which is analogous to actual geological formations such as the Mount Simon Sandstone unit. The CO₂ injection simulation used a cylindrical grid setting in which the injection well was situated at the center of the domain, which extended out 8,000 m from the injection well. The CO₂ migration was simulated using the latest version of the simulator, subsurface transport over multiple phases (the water–salt–CO₂–energy module), developed by Pacific Northwest National Laboratory. A nonlinear parameter estimation and optimization modeling software package, Parameter ESTimation (PEST), is adopted for automated reservoir parameter estimation. The effects of data quality, data worth, and data redundancy were explored regarding the detectability of reservoir parameters using gas pressure monitoring data, by comparing PEST inversion results using data with different levels of noises, various numbers of monitoring wells and locations, and different data collection spacing and temporal sampling intervals. This study yielded insight into the use of CO₂ monitoring data for reservoir characterization and how to design the monitoring system to optimize data worth and reduce data redundancy. The feasibility of using CO₂ saturation data for improving reservoir characterization was also discussed.     

Estimation of petrophysical parameters using seismic inversion and neural network modeling in Upper Assam basin,India

Estimation of petrophysical parameters is an important issue of any reservoirs. Porosity, volume of shale and water saturation has been evaluated for reservoirs of Upper Assam basin, located in northeastern India from well log and seismic data. Absolute acoustic impedance (AAI) and relative acoustic impedance (RAI) are generated from model based inversion of 2-D post-stack seismic data. The top of geological formation, sand reservoirs, shale layers and discontinuities at faults are detected in RAI section under the study area. Tipam Sandstone (TS) and Barail Arenaceous Sandstone (BAS) are the main reservoirs, delineated from the logs of available wells and RAI section. Porosity section is obtained using porosity wavelet and porosity reflectivity from post-stack seismic data. Two multilayered feed forward neural network (MLFN) models are created with inputs: AAI, porosity, density and shear impedance and outputs: volume of shale and water saturation with single hidden layer. The estimated average porosity in TS and BAS reservoir varies from 30% to 36% and 18% to 30% respectively. The volume of shale and water saturation ranges from 10% to 30% and 20% to 60% in TS reservoir and 28% to 30% and 23% to 55% in BAS reservoir respectively.     

三维地震约束辫状河储层的多点统计建模研究:以委内瑞拉M区块为例

将地震信息引入多点统计地质建模之中,可以提高模型的井间预测功能.首先以委内瑞拉奥里诺科重油带一个辫状河沉积含油区块为例,结合该区辫状河储层的地质特点,利用井震信息结合的多点统计建模方法,研究了波阻抗的相标定、砂体概率生成曲线选定、训练图像分析、井震影响比等方面的技术细节及它们在辫状河储层多点统计建模中的作用.然后结合辫状河储层的沉积学特征,对研究区的心滩、河道、泛滥平原等微相空间分布的建模结果进行了分析.最后对于不同的储层建模结果进行了不确定性分析.研究表明:井震结合的多点统计建模方法,较好地降低了稀井网地区建模结果的不确定性;通过砂岩概率生成曲线,波阻抗数据转化为地震相的空间概率分布.这样就有效地建立起了地震数据与其地质意义的联系;相比仅用测井信息建模,井震结合建模结果对井间微相预测更具合理性,同时预测的河道、心滩的连续性也得到了更好的体现.      

现代油藏描述关键技术

现代油藏描述提倡勘探开发一体化,真正实现测井与地震信息匹配,实现静态信息与动态信息结合,最终由定性走向定量。重点阐述了现代油藏描述中,通过集成高分辨率的岩石物理数据、中分辨率的测井数据及低分辨率的地震数据,采用储层自动划分对比及储层结构分析技术、沉积微相自动识别技术、波形差异分析法预测高产气区技术对不同勘探开发阶段、不...     

利用井约束反演技术进行油藏描述研究

论述了一种针对薄互储层条件下的油藏描述方法，以井约束反演技术为基础，利用对岩性变化敏感的测井曲线进行井约束条件下的二维地震资料储层反演处理，大大提高了地震资料的分辨率，为砂泥岩薄互层储层预测奠定了基础。     

Rock physics template (RPT) analysis of well logs and seismic data for lithology and fluid classification in Cambay Basin

The Cambay Basin is 450-km-long north–south-trending graben with an average width of 50 km, having maximum depth of about 7 km. The origin of the Cambay and other Basins on the western margin of India are related to the break up of the Gondwana super-continent in the Late-Triassic to Early-Jurassic (215 ma). The structural disposition of the Pre-Cambrian basement—a complex of igneous and metamorphic rocks exposed in the vicinity of the Cambay Basin—controls its architecture. The principal lineaments in the Basin are aligned towards NE-SE, ENE-WSW and NNW-SSE, respectively. Rock physics templates (RPTs) are charts and graphs generated by using rock physics models, constrained by local geology, that serve as tools for lithology and fluid differentiation. RPT can act as a powerful tool in validating hydrocarbon anomalies in undrilled areas and assist in seismic interpretation and prospect evaluation. However, the success of RPT analysis depends on the availability of the local geological information and the use of the proper model. RPT analysis has been performed on well logs and seismic data of a particular study area in mid Cambay Basin. Rock physics diagnostic approach is adopted in the study area placed at mid Cambay Basin to estimate the volume in the reservoir sands from 6 wells (namely; A, B, C, D, E and F) where oil was already encountered in one well, D. In the study area, hydrocarbon prospective zone has been marked through compressional (P wave) and shear wave (S wave) impedance only. In the RPT analysis, we have plotted different kinds of graphical responses of Lame’s parameters, which are the function of P-wave velocity, S-wave velocity and density. The discrete thin sand reservoirs have been delineated through the RPT analysis. The reservoir pay sand thickness map of the study area has also been derived from RPT analysis and fluid characterization. Through this fluid characterization, oil-bearing thin sand layers have been found in well E including well D. The sand distribution results prove that this methodology has able to perform reservoir characterization and seismic data interpretation more quantitatively and efficiently.     

川东建南地区石炭系地震储层预测

川东建南地区上石炭统黄龙组残余厚度一般在0～30 m,岩性以白云岩、石灰岩和角砾岩为主,且以前两类的储集物性较好。白云岩类是工区石炭系最重要的储集层,在白云岩类储层中又以针孔白云岩最好;石灰岩类储层中以角砾状灰岩较好。利用三维地震资料所作的属性定量分析、波阻抗反演及厚度预测等储层预测工作表明,黄龙组储层较围岩具有高阻抗的特点,其中物性最好的针孔白云岩表现为高阻抗背景下的低阻抗特征,物性较差的角砾白云岩表现为高阻抗特征。储层的测井响应特征及地震响应特征分析发现,当地震剖面存在双强相位(双轨特征)时,黄龙组地层存在,而当地震剖面呈现单轨特征时,则黄龙组地层不存在;地震振幅强弱与黄龙组厚度密切相关。利用地震属性及波阻抗反演技术同时预测储层厚度,其结果与实钻结果相当吻合。     

塔中地区卡塔克1区块东河砂岩地震储层预测研究

采用基于地震波形分类的地震相分析与沉积相解释、波阻抗约束稀疏脉冲反演、地震多属性储层预测及油气检测等针对岩性油气藏的储层地震预测技术，从塔中地区卡塔克1区块泥盆系东河砂岩储层的生储盖组合条件及相关的地震地质特点出发，利用卡1三维地震资料开展目的层系的目标精细解释，结合已有的钻探、测井和测试等资料，揭示了东河砂岩储层砂体的空间展布特征，圈定出砂岩发育带，并对有利储层段的潜在含油气性进行了综合预测和评价。     

塔里木盆地下寒武统肖尔布拉克组北部台缘带展布及其油气勘探意义

礁滩型白云岩是世界范围内油气勘探开发效果最好的领域之一。塔里木盆地震旦-寒武系具备规模礁滩型白云岩发育基础,但其特征与分布研究基础十分薄弱。本文采用野外剖面观察、单井资料分析、地震资料刻画等手段,落实了柯坪-塔北西部存在下寒武统台缘带,命名为北部台缘带,该台缘带呈北东走向,长约330 km,宽约7 km。野外露头资料显示,下寒武统北部台缘带发育两期微生物礁,岩性以针孔状白云岩为主,溶蚀孔洞发育;地震剖面上,可见丘状前积反射特征。北部台缘带具有得天独厚的生储盖配置优势,位于长期继承性发育的古隆起之上,具备形成大油气田的有利条件。北部台缘带的展布特征为该区下古生界白云岩的区带评价及目标优选指明了方向。     

珠江口盆地H区块碳酸盐岩储层地震沉积学应用研究

珠江口盆地H区块中新世珠江组碳酸盐储层研究存在两个棘手的问题,一是储层厚度薄,单层厚度在6~35 m之间,普遍小于纵向分辨率四分一波长;二是储层非均质性强、相变快,受沉积相控制明显,但区内尚未开展区域碳酸盐岩沉积相研究,沉积相类型及分布尚不清楚.针对上述问题,开展了以地震相分析为辅助,利用测井、录井划分的单井沉积相,再结合以岩性和地震波阻抗之间建立的岩石物理关系标定叠前反演的弹性阻抗数据体,尝试在研究区进行地震沉积成像研究,识别并圈定有利储集相带的台缘礁、台内礁、台内滩体的范围,综合划分的有利储层在工区钻井上得到了良好印证.     

Importance of coloured inversion technique for thin hydrocarbon sand reservoir detection – A case in mid Cambay basin

Cambay basin is an intra-cratonic rift graben formed as a result of rifting which was occurred in late Cretaceous with Deccan lava eruption through linear trending NNW to SSE directional basin. The Deccan basalt forms the basement over which more than 7–11 km thick piles of Tertiary sediments have been deposited during syn-rift and post-rift phases of basin development. Cambay basin has been considered as one of the significant hydrocarbon prolific basin in India. The biggest challenge in current days for this basin is further exploration or exploration under development stage in small marginal field or unexplored left out areas in the basin part as most of the areas are already explored/discovered by various small to big E&;P (exploration &; production) industrial players. In this present study one such small marginal field has been chosen for “Exploration under Development” portfolio in mid Cambay basin. The amount of oil-in-place volume, investment and techno-economics analysis of small marginal field has made this study area. In view of further hydrocarbon exploration in this area this kind of study will provide a robust support in limited dataset. The reservoir sand quality of the study area is discrete, thin and less permeable. This kind of sand body detection through classical seismic interpretation approach is difficult and there will be always a big amount of uncertainties for findings the pay reservoir sand. In view of the limitation of available data and challenging geological setup of the reservoir, a quantitative approach has been taken to detect the thin reservoir sand in this study area. Primarily coloured inversion technique has been applied on post-stack seismic data based upon well to seismic correlation and reservoir sand detection in seismic interpretation and well log property analysis. This technique has produced higher detectability impedance/property volume with respect to normal post-stack seismic data signature. Based on high contrast impedance/elastic property further seismic based attribute analysis on reservoir section has been performed. The attribute analysis has been made along surface and 3D seismic data level, provided clear image about the thin hydrocarbon sand reservoir. Based upon quantitative interpretation approach coloured inverted volume the prospect was chosen for further drilling in the study area and drilling of that sand was turned to be a hydrocarbon discovery prospect. The unconventional approaches e.g. coloured inversion with limited dataset for this kind of small marginal field has potential to find the hydrocarbon.     

河流相储层构型研究新理论、新方法——海上油田河流相复合砂体构型概念、内容及表征方法

基于陆上油田密井网的河流相储层构型研究,经过数十年积累,理论基础及表征方法已比较成熟,然而,将其应用于海上油田稀疏井网条件时,依然面临较大的挑战。笔者团队经过多年探索,基于海上油田开发地质研究方法,形成了井震结合、以"复合砂体"为核心的海上河流相复合砂体构型理论与表征方法,其特点在于运用三维原型建模、地震构型相预测及地震驱动确定性建模等技术,重点表征影响海上油田开发的五、六、七级构型单元(复合河道带、单一河道带、复合点坝),针对开发阶段的小层细分对比及不连续渗流屏障刻画等方面具有明显的优势。目前,应用这套理论及方法开展精细地质建模和数值模拟依然存在挑战,需要进一步发挥地震资料作用并探索人工智能的地震解释新途径。