CARBONATE GEOBODIES: HIERARCHICAL CLASSIFICATION AND DATABASE – A NEW WORKFLOW FOR 3D RESERVOIR MODELLING

Quantitative data on geobodies are crucial for reservoir modelling. Although abundant quantitative data are available in the literature for siliciclastic depositional systems, equivalent data for carbonate systems are scarce. In this paper we introduce a new approach to the management of quantitative data on carbonate geobodies which is based on a hierarchical classification scheme. The classes to which a carbonate geobody are assigned are: (1) depo‐time (i.e. geological age); (2) depo‐system (i.e. type of carbonate platform); (3) depo‐zone (i.e. facies belt or zone); (4) depo‐shape (i.e. geometry of the geological body); (5) depo‐element (i.e. architectural elements present); and (6) depo‐facies (litho‐ and biofacies). This hierarchical classification is complemented by a set of rules for modifying depo‐shapes which refer to their spatial distribution and patterns of interaction. Based on this classification, an extensive database has been developed which can be used for 3D reservoir modelling. The database holds more than 600 case studies from outcrop analogues and the subsurface and also from satellite images of modern carbonate settings. The database can be used as the basis for a new workflow for reservoir modelling which uses multiple‐point statistics (MPS). MPS makes use of training images to capture and reproduce facies patterns and geometries during stochastic simulations. The application of this new approach is demonstrated by modelling a Cretaceous outcrop reservoir analogue from southern France. The use of MPS allows the generation of geologically realistic and complex facies distributions in the model based on the simplified training images.     

Stochastic surface modeling of deepwater depositional systems for improved reservoir models

High resolution reservoir models are often required for resource assessment and reservoir management. The reservoir models must reproduce geologically realistic heterogeneity that may affect predictions. An important heterogeneity in many deepwater depositional systems consists of facies variations controlled by geological events that lead to lobe geometries. A surface-based geostatistical scheme is presented to model high resolution lobes and their associated stacking patterns in a geometrically realistic manner. The lobes are constrained to match well data. Facies, porosity and permeability are then modeled within the lobe framework. Application to a reservoir with 36 wells demonstrates the practical applicability of the approach. This surface-based method may be readily extended to model other geometries in various reservoir settings.     

沉积相耦合岩石物理类型的孔隙型碳酸盐岩油藏建模方法

定量表征孔渗和饱和度的三维空间分布是孔隙型碳酸盐岩油藏开发的技术难题。为建立可靠的孔隙型碳酸盐岩油藏地质模型,以扎格罗斯盆地F油藏为原型,研究并提出了沉积相耦合岩石物理类型的建模方法。该方法在地质研究的基础上,通过井-震联合建立沉积相模型;再以沉积相控制建立孔隙度和岩石物理类型三维分布模型;然后基于岩石物理类型控制下的孔渗关系数学模型和饱和度数学模型,采用确定性建模方法,建立渗透率和饱和度三维分布模型。模型检验表明,该方法建立的地质模型可靠,为F油藏的有效开发奠定了坚实的地质基础,可为该类油藏的地质建模提供指导。      

准噶尔盆地庄1井区J_1S_2~2砂组储层沉积模式及随机建模研究

通过井震联合得出储层沉积模式,然后以反演数据体为二级变量,通过同位协同模拟方法对自然 电位场进行随机模拟,再以每个自然电位场为约束,应用示性点过程方法建立多个储层三维相模型,最 后优选模型作为相约束,应用序贯高斯模拟方法建立储层参数模型。这种逐级约束、多级建模的方法在 区内取得了较好建模效果。     

龙岗地区礁滩气藏地质建模方法探索

针对四川盆地龙岗地区礁滩储层非均质性强及气藏气水关系复杂、地质建模存在诸多技术难题的现状,开展了三维地质建模的探索工作,并总结形成了以“双相控制,分步建模”技术方法为核心的复杂礁滩气藏建模技术。其建模思路及技术对策为：①突破等时地层界面,以储渗体为研究单元;②沉积相建模确定气藏大的沉积背景及格局;③确定岩性在空间的分布规律,精细刻画储渗体空间的非均质性;④采用局部建模与整体建模相结合的分步建模方法;⑤采用随机与确定性建模相结合的技术方法。模型验证结果表明,该建模技术适用于龙岗地区以及稀井网条件下储层非均质性强、气水关系复杂的礁滩型碳酸盐岩气藏的整体描述。     

碳酸盐岩缝洞型油藏三维地质建模方法——以塔河油田四区奥陶系油藏为例

碳酸盐岩缝洞型油藏储集空间类型主要为大型溶洞、溶蚀孔洞及裂缝,尺度大小悬殊,形态不规则,分布不连续。定量刻画孔、洞、缝在三维空间的展布一直是该类油藏开发的技术难题,目前尚缺乏有效的地质建模方法。以塔河碳酸盐岩缝洞型油藏为原型,提出了多元约束碳酸盐岩缝洞型油藏三维地质建模方法,即在古岩溶发育模式控制下,采用两步法建模。第一步,建立4个单一类型储集体模型:首先利用地震识别的大型溶洞和大尺度裂缝,通过确定性建模方法,建立离散大型溶洞模型和离散大尺度裂缝模型;然后在岩溶相控约束下,基于溶洞发育概率体和井间裂缝发育概率体,采用随机建模多属性协同模拟方法,建立溶蚀孔洞模型和小尺度离散裂缝模型。第二步,采用同位条件赋值算法,将4个单一类型模型融合成多尺度离散缝洞储集体三维地质模型。该模型定量刻画了缝洞储集体在三维空间的展布特征,为油田开发奠定了坚实的地质基础。     

基于相序的多点地质统计学相建模方法及其应用

目前的多点地质统计建模方法均以一定维度的数据模板为载体,将概率或几何距离作为建模工区未知区域模拟取值的判定标准,该判定标准在地质建模时与地质含义的联系较为薄弱。针对上述不足,文章回归地质建模的本质,考虑相建模过程中数据事件与训练图型对比的地质含义,提出基于相序的多点地质统计相建模方法。该方法以具有沉积学意义的相序为基本的相似度对比单元,新建适合于相序相似度对比的动态数据模板,采用句法模式识别技术,通过动态规划方法计算数据事件中已知相序与训练图型中对应相序的相似度,对建模工区未知区域进行相模拟,实现了从沉积学意义出发对强非均质性储层进行多点地质统计学建模。理想模型和塔河X区三角洲前缘储层沉积相模拟表明,本文方法能够有效重现训练图像所显示的各地质体的几何形态,较好地反映储层不同相的沉积展布规律,大幅提高了相建模的精度。该方法将沉积学与多点地质统计学有效结合,提出了一种全新的多点地质统计学相似度对比方法和多点地质统计学建模框架,为复杂储层的相建模提供了一种新的方法。     

储层随机建模方法在细分沉积相中的应用

以SN油田S109井区油藏为研究对象，在储层构造、沉积微相、测井解释、储层非均质等研 究基础上，建立地质数据库，应用三维可视化技术对油藏构造、沉积微相和油藏属性建立三 维模型，通过建立的储层三维模型，对沉积微相划分等地质工作进行了检验和修改，从而建 立起符合研究区的沉积微相及储层物性分布，为后续油藏数值模拟工作打下基础。     

THE IMPACT OF DATA INTEGRATION ON GEOSTATISTICAL POROSITY MODELLING: A CASE STUDY FROM THE BERRI FIELD, SAUDI ARABIA

Understanding the spatial distribution of reservoir properties such as lithology and porosity is essential for development drilling, reserves estimation and fluid flow simulation. However, the data typically come from various sources at various scales and have varying degrees of reliability. Data such as wells logs and cores on their own are generally not adequate to produce an accurate model of a reservoir. Geostatistics provides a means for geologists and engineers to analyze this data, and to transfer the resulting analyses and interpretations for the purpose of reservoir modelling and forecasting. The objective of this paper is to assess the added value that is gained by integrating different types of data (such as depositional facies and seismic impedance) with 3‐D geostatistical porosity models. To achieve this goal, four porosity models of the Hanifa Reservoir at the Berri field (Saudi Arabia) were built using different geostatistical modelling algorithms. The first porosity model was based solely on porosity logs from wells. The other three porosity models were generated using different combinations of porosity logs, depositional facies and seismic impedance data. These models were evaluated qualitatively and quantitatively. The results of this study show that facies‐based porosity models result in the better definition of porosity both vertically and laterally compared to the other models. The seismic‐controlled model was the most precise—seismic data has a greater sample density than well data. Porosity from the wells‐only model has the lowest accuracy compared to the other models, which shows the importance of introducing other types of data in porosity modelling. It is concluded that the utilization of different data sources has a pronounced positive impact when modelling areas with low sampling density. Integrating seismic impedance and facies data in porosity modeling improves the overall model accuracy and generates more reliable images about reservoir heterogeneity.     

岩相骨架的地质统计模拟

储集层非均质性是碎屑岩储集层描述中的重要问题。与流体性质分布的不确定性相比，岩相骨架的不确定性对流体预测影响更大。近十年来，地质统计方法大量地应用于岩相骨架的模拟中，其模拟方法主要有离散及连续两类。用数学语言对４个主要的离散模拟方法（序贯指示模拟、截断高斯模拟、模拟退火及示性点过程模拟）进行概述，展示其工作过程，讨论各自的优缺点，特别强调如何合并次生数据以及在现场应用的可能性。此外，还提出了该领域未来的研究方向。表１参２９（邹冬平摘     

松辽盆地茂8井三维地震区薄互层储层预测方法及效果

本文针对松辽盆地陆相薄互层的沉积特点,结合茂８井三维地震区块的实际情况,采用“滑动相关法”确定地震地质层位,准确标定了各反射同相轴的地质含义。依据砂岩或砂层组在三维剖面上的特征,充分发挥人机联作解释系统的优势,利用振幅、频率对主要含油层系砂岩的横向变化进行了深入研究,经钻井验证取得了较好的效果。     

多点地质统计学在致密砂岩气藏储层建模中的应用——以s48-17-64区块为例

苏里格气田致密砂岩气藏非均质性强,沉积微相规律性差,地质建模难度大。参考其他随机性地质建模方法,优选多点地质统计学地质建模,综合基于目标和基于象元的优势,提出了＂井-震-地质统计学规律＂的综合一体化随机性地质建模思路。在苏里格气田西区s48-17-64区块,基于前期地质认识和密井网砂体解剖,以盒8下辫状河沉积微相模式作为多点地质统计学的训练图像,三维地震资料为软约束体,离散化测井数据为硬数据体,井震结合建立三维地质模型,并采用不断完钻的气井验证地质模型,二次建模。经过验证,该方法建立的地质模型精度高,降低了随机建模离散化问题,在开发实践中发挥了积极作用,展示了良好的应用前景。     

塔河油田奥陶系缝洞型碳酸盐岩储集层三维地质建模

塔河油田奥陶系碳酸盐岩油藏是以溶蚀孔洞及裂缝为主要储集空间的古岩溶型储集层，储集层非均质性极为严重。为制定试验区稳油控水综合治理方案，运用地震方差体技术、云变换技术、岩溶相控建模技术等综合地质、地球物理和油藏工程资料，通过构造建模、岩溶建模、属性建模、裂缝分析及模型分析筛选开展储集层三维地质建模研究，改善了缝洞型碳酸盐岩储集层三维地质随机建模方案，为该区油藏精细描述和数值模拟提供了合理的地质模型。随机模拟结果表明，塔河油田奥陶系碳酸盐岩有利储集层与构造高部位存在一致性，且储集体的发育与构造变形程度及岩溶作用有关；孔隙度和渗透率的值均较低，分布具有随机性，整体表现为北东高，向南变低的趋势，由浅到深随井数减少不确定性增加，图9参16.     

“化学-沉积相”分析：一种研究细粒沉积岩的有效方法

细粒沉积岩作为致密油气和页岩油气重要的勘探对象,具有粒度细、颜色均匀、非均质性强等特点,传统的岩心观察方法难以适用于细粒沉积岩的精细研究。通过获取细粒沉积岩手标本（岩心尺度）高分辨率（30 μm）的二维原位无机地球化学元素分布信息,结合图像分析,建立岩心尺度精细的“化学-沉积相”模型。在模型中,可以根据无机地球化学元素的平面分布清晰的识别细粒沉积岩的矿物成分和沉积构造。在此基础之上,能够提取不同部位的原位地球化学信息,针对细粒沉积岩沉积周期长厚度小的特点,实现在毫米-厘米级尺度上表征古环境、沉积物来源和成因,同时避免常规测试中粉碎均一化样品后所造成的信息干扰,为致密油气与页岩油气的勘探开发提供更加精细的沉积相模型和可靠的数据来源。     

鄂尔多斯盆地苏里格气田Z30区块储层地质建模

地质建模可以定量、直观地展示储层三维物性参数及几何形态,提高井间物性的内插精度,从而提高储层精细描述的精确度。苏里格气田东区Z30区块储层发育于河流相,砂体横向变化快,储层预测难度较大,故利用Petrel软件,以钻井数据为基准,按照点-面-体的建模步骤建立Z30区块构造模型;在此基础上,以测井解释单井相数据为基准,采用序贯指示模拟方法构建了沉积微相模型;并以相控建模技术为指导,采用序贯高斯模拟方法建立了储层属性模型。储层建模研究为准确评价储层性质及潜     

FACIES HETEROGENEITIES IN A RAMP CARBONATE RESERVOIR ANALOGUE: A NEW HIGH‐RESOLUTION APPROACH FOR 3D FACIES MODELLING

In contrast to the conventional view that facies distribution patterns on carbonate ramps are relatively simple, outcrop analogue studies point to a high degree of internal facies complexity. Depending on the diagenetic overprint, this complex pattern may result in reservoir compartmentalization due to the presence of interflow baffles. The often subseismic scale heterogeneities may not be included in conventional reservoir modelling. In order to evaluate how facies heterogeneities in shoal reservoirs can be modelled realistically, this paper presents a facies modelling workflow which includes a new approach to the design of training images for multiple‐point statistics (MPS). The workflow was developed in the course of a reservoir outcrop analogue study of a Ladinian (Middle Triassic) coquinadominated shoal complex in SW Germany which was deposited on an epicontinental, gently inclined carbonate ramp. The data set was based on an intensive field study and includes 3D facies and sequence stratigraphic analyses of the largest shoal complex in the Quaderkalk Formation (Upper Muschelkalk). This several metre thick shoal complex represents a subseismic scale, bioclast‐rich reservoir analogue and has a very heterogeneous facies pattern. Integrating 1D facies logs and sequence stratigraphic trends from tens of outcrop sections and cores, two nested 3D geocellular facies models were produced: (i) a large‐scale (30 × 30 km) model based on truncated Gaussian simulation (TGS); this formed the basis for (ii) a smaller‐scale (10 × 10 km), more detailed model based on multiple point statistics. In addition, a new approach for training image design was developed to honour small‐scale sequence stratigraphic trends and lateral facies patterns observed in modern analogues. Compared to facies patterns in modern analogues, the large‐scale model presents geologically‐feasible facies distribution patterns and geometries, and in addition shows a vertical facies distribution which is similar to the observed sequence stratigraphic architecture of the outcrop data‐set used. Due to the new training image design, the final small‐scale model has a distribution pattern of facies heterogeneities which looks similar to modern facies distributions in the offshore UAE and thus represents a valuable method of producing realistic reservoir facies models. The modelling workflow and the new approach for training image design presented will help to reduce uncertainties in the understanding and modelling of subsurface reservoirs by using a systematic combination of outcrop data and modern analogues, with the consistent application of sequence stratigraphic principles. In addition, this study emphasises the importance of careful training image design, derived from modern analogues, which can be used as realistic inputs in order to optimize multiple point simulations, and which may be applied to producing bioclastic reservoirs such as those located on the Arabian Plate or offshore Brazil.     

一种基于对抗神经网络的方法在钻井数据恢复中的应用

机器学习中数据缺失很普遍，导致数据缺失的因素通常有人为失误、数据处理软件的缺陷、获取数据的传感器错误等。数据缺失会导致机器学习的性能下降，因此缺失值的填补对机器学习任务变得格外重要。针对数据缺失问题，该文提出一种新颖的缺失数据填补方法，构建了一个生成对抗填补网络（简称GAIN）。GAIN主要包括生成器和判别器两个部分，其中生成器（G）用来观察真实数据的每一部分，然后根据观察的结果填补缺失数据的部分，输出一个填补后完整的向量；判别器（D）接受一个完整的向量，来判别哪一部分数据是真实的，哪一部分是被填补的。在4个UCI机器学习标准数据集和石油行业钻井液数据集间进行了实验，验证了GAIN方法的有效性，能提升机器学习任务的性能。     

复杂地质特征下的构造建模——以辽河油田曙二区大凌河油层为例

三维地质建模技术成为了现代油藏描述成果有力的表达工具。在辽河油田曙二区大凌河油层的构造建模工作中,在地震反射层面的趋势约束下,基于地质分层数据建立了工区地质体的地质层面模型;利用地质研究的断点数据对地震解释的断面进行归位处理,建立了工区地质体的断面模型;针对断面之间、地质层面间以及断面和地质层面的空间关系进行处理,生成地质体三维骨架网格,最终建立了工区地质体的构造模型。     

电成像测井资料在东营凹陷北带砂砾岩体沉积相分析中的应用

利用微电阻率成像测井（FMI）资料,并结合岩心、常规测井、地质资料,对东营凹陷北带东段盐家油气田进行了砂砾岩地层沉积旋回的划分和沉积亚相及微相特征的提取,总结了该区电成像图像形态及颜色所反映的岩性识别模式、沉积构造识别模式和沉积亚相识别模式,为该区砂砾岩体沉积相的深入研究奠定了基础。     

Regional probability perturbations for history matching

Reservoir simulation is ubiquitous in the petroleum industry, and conditioning models to production data (history matching) has become an essential job of reservoir engineers. Traditional history-matching methods directly perturb reservoir properties without regard to the existing geological continuity. When the geological heterogeneity is destroyed, the result is often a history-matched model with little prediction power. This paper presents a method for matching historical production data and, at the same time, honoring large-scale geologic information that is obtained from stratigraphic and sedimentological interpretations. Geostatistical simulation methods are used to inject the interpreted geological heterogeneity into a reservoir model. In order to maintain geological continuity in the history match models, we propose a method that perturbs the probability models used to simulate the geological model. Regional perturbations are incorporated to make the method practical for field cases that have numerous wells and local geologic differences. We demonstrate that the proposed approach does not create geological artifacts at the region borders. Additionally, a new simple yet efficient optimization method that can jointly optimize the magnitude of the perturbations for a large number of regions is proposed. A number of realistic synthetic examples demonstrate the method under various geological scenarios and several production data matching criteria. A realistic 3D synthetic simulation model based on a North Sea fluvial channel-type reservoir demonstrates how the method would work in practice. The current work provides reservoir engineers with an additional tool to use in the history-matching process.