【作者】 姜平；

【导师】 姚光庆；

【作者基本信息】 中国地质大学 ， 油气田开发工程， 2014， 博士

【摘要】 随着油田勘探开发形势的发展,对陆上油气藏的研究刻画逐渐精细,海上的油气藏的勘探,也进入以小砂体、小断块、结构复杂、低渗透率,及各种非均质性极强的复杂地质体为目标的勘探和开发阶段。我国海洋领域油气生产不可避免的进入“复杂储层”为对象的阶段,评价手段、工程措施和开发措施都要为此精细设计。本文以北部湾盆地涠西南凹陷复杂储层油田(涠洲11-4N、涠洲11-1、涠洲11-1N、涠洲11-2)流沙港组为例,通过综合储层表征与评价技术,开展复杂储层精细沉积学和复杂储层综合指标体系综合定量评价的研究,从成因上分析研究区沉积储层的形成过程及其三维空间的变化规律,从研究方法上建立复杂储层评价研究体系和具体技术方法,为本区油藏开发方案的制定或调整提供扎实基础。论文以层序地层学、沉积学、储层地质学、测井地质学理论为指导,综合利用地震、岩心、测井、生产测试及开发井生产动态等资料建立了构造-沉积的层序地层格架,并进行复杂沉积体系控制因素分析,对重点层位储层沉积微相的垂向与平面分布进一步细化,分析砂体的垂向叠置关系、连通性与平面分布规律,建立不同沉积体系内不同成因砂体的砂岩厚度与宽度的经验公式和宏观非均质性参数,系统研究储层的物性特征,分析有效储层和储层物性与沉积微相之间的关系,确定有利物性区,并利用地质统计学法进行权衡定量评价,对储层进行分类,最后采用相控随机三维地质建模技术,建立油田尺度复杂储层定量化地质模型,在三维空间上表征储层结构单元、物性单元和有利储集带,为油田开发方案实施提供确定性依据。本论文研究取得的研究成果和主要认识可以概括为以下几个方面：以地震、岩心及测井资料为基础,以界面识别为准则、结合油组划分、可容纳空间变化研究,结合原有油藏的划分进行基准面旋回分析,综合了沉积层序、T-R层序和Cross.TA的高分辨率层序地层理论,建立了流沙港组统一的精细的层序格架。在流一段识别了两个长期旋回,9个中期旋回和24个短期旋回,在流三段识别了一个长期旋回,5个中期旋回和24个短期旋回。同时依据研究区内井位分布情况、砂体展布特征和全区层序划分结果,目的层自下而上划分了5个油组,8套砂体,砂体横向连通性较差,各个油组在平面分属不同的砂体,其中主力油组V油组又划分V1和V2两个小层。从砂体发育和重矿物定量分析来看,流一段上层序北部稳定重矿物组合主要为白钛矿、赤褐铁矿、锆石与电气石这四种,总体上来看物源主要来自西部,呈W-E向展布,流一段下层序北部稳定重矿物组合主要为电气石、白钛石、锆石和赤褐铁矿四种,南部为锆石、电气石和白钛石,总体上来看物源主要来自西南,呈WS-EN向展布。流三段稳定重矿物主要有白钛矿、赤褐铁矿、锆石和电气石,从重矿物组合特征上分析,其物源主要来自南西部。岩性特征方面,流一段上层序岩性整体偏细,主要为细砂岩、粉细砂岩和泥岩,沉积构造有槽状交错层理,板状交错层理,小型沙纹层理,小型爬升层理,水平层理和变形层理,主要表现为牵引流沉积作用,局部可见重力流变形和负载构造,而中层序与下层序岩性整体偏粗,主要为砂砾岩、含砾粗砂岩、中粗砂岩和薄层的粉细砂岩和泥岩,沉积构造主要为槽状交错层理、板状交错层理、复合层理。流三段主要识别出粒序层理,沙纹层理,板状交错层理,块状层理,槽状交错层理和生物扰动构造。通过对岩心观察与精细描述,将研究区流一段上测井相分为箱型、钟形、漏斗形、指形、线形,流一段中和流一段下再细分出箱型-漏斗形组合、钟形-钟形组合型、漏斗形-指形组合、箱型-箱型组合以及箱型-指形组合,综合岩心和测井相的详细分析,认为流一段上为正常三角洲前缘沉积,主要为水下分流河道、河口坝、远砂坝、席状砂和水道间等沉积微相,流一段中为扇三角洲前缘沉积,内前缘沉积主要微相为辫状水道、辫流坝、河口坝、席状砂和水道间,外前缘主要微相为分支水道、河口坝、远砂坝、席状砂和水道间,流一段下层序为扇三角洲前缘沉积,细分为扇三角洲内前缘和外前缘2种亚相,进一步细分为8种亚相。流三段上部为扇三角洲外前缘沉积,分为4种微相,下部为扇三角洲内前缘沉积,细分出5种微相,内前缘主要微相为辫状水道、辫流坝、河口坝、席状砂和水道间,外前缘主要微相为分支水道、河口坝、远砂坝、席状砂和水道间。在详细的岩心观察和砂体对比的基础上,总结了各类砂体的接触关系模式,将砂体叠置模式分为6大类8小类,即辫流坝与辫流坝模式、辫状水道与辫流坝模式、辫状水道与辫状水道模式、分支水道与分支水道模式、分支水道与河口坝模式、分支水道与席状砂模式。正常三角洲微相中,河口坝、水下分流河道和远砂坝平均厚度分别为3.4m、3m、1.9m,平均宽度分别为296m、294.8m、207.1m,宽厚比分别为100.9、110.7、115.9。辫状河三角洲中,河口坝、水下分流河道平均厚度分别为4.2m、6.3m,宽度分别为350.9m、348m,宽厚比分别为84.3m、70.3m。扇三角洲中,辫状水道、辫流坝、分支水道、河口坝平均厚度分别为3.6m、4.3m、4.1m、2.7m,平均宽度分别为646.1m、783.2m、748.3m、683.9m,平均宽厚比分别为223.2、242.2、253.7、606.3。利用岩心样品物性测试资料,分析了流沙港组物性变化规律。流三段孔隙度在12%-18%之间,渗透率在24-294md之间,孔隙度和渗透率分布图表明河道的物性相对最好,主要集中在WZ11.1-A5_WZ11-1-2_WZ11-1-A10_WZ11-1-A8井附件。通过对流沙港组夹层和渗透率变异系数的详细研究,认为辫状水道孔隙度和渗透率呈现正韵律特征,河口坝孔隙度和渗透率呈现反韵律特征,WZ11-1N-2井和WZ11-1N-A井附近的渗透率变异数最高(平均达到2.4),非均质性最强。通过测井-地震联合技术对砂体进行详细追踪,发现流一段上层序正常三角洲沉积的砂体在地震剖面上连续性差,呈孤立或条带状分布,而流一段中～下层序扇三角洲前缘沉积砂体多以砂砾岩和粗砂岩为主,沉积厚度较大,远离物源时,表现为薄层的辫状水道沉积与相对较厚的水道间泥岩沉积的互层。流三段共发育12个砂体,在地震剖面上为中强振幅,连续性较好,从平面分布图来看,靠近物源的北部砂体分布特点为大而少,南部砂体特点为小而多。结合实测数据和测井数据对复杂储层参数进行了综合评价。论文采用密度测井和中子测井建立了孔隙度解释模型,分中砂以上粒级和中砂以下粒级分别建立孔渗关系,同时结合6口井的578个样品点,利用RQI和Φz将研究区划分4类流动单元,并按照不同流动单元建立渗透率解释模型,结果表明在流动单元的控制下的孔渗模型相关性较高,相关系数在0.8以上。通过储层四性关系的研究,认为流沙港组主要好储层岩性为粗粒级岩性,粗砂及以上粒级岩性以高渗储层为主,细粒级岩性(如粉砂岩)以低渗储层为主,总体上储层渗透率以中高渗储层为主,孔隙度和渗透率下限分别为14%、2md,泥质含量上限为15%。并且总体上流沙港组敏感性表现为无速敏或中弱速敏、中弱酸敏、中弱应力敏感性,速敏原因主要与岩样中可运移的粘十矿物高岭石颗粒大小产状与孔喉匹配有关,强酸敏和强应力敏感性仅在个别样品出现。在对流沙港组复杂储层现有测试工作制度分析的基础之上,针对不同的储层物性分别提出了不同的测试工作制度,编制了一套计算合理测试时间的程序。同时分析了启动压力梯度和渗透率应力敏感效应对产能的影响,并综合区域的地质油藏认识,提出了适合本区域的产能预测方法。最后认为“一开一关”测试方式对流沙港组复杂低渗储层最合适,并且孔隙度大于17%时才能获得高产,随着渗透率的增大,比采油指数呈增大的趋势,进一步说明渗透率是影响油田油井产能的重要因素,生产井的部署要充分考虑储层的渗透性。复杂储层产能-埋深关系、复杂储层产能-沉积环境关系表明在同一深度下,异常高压的储层的产能相对较好,水下分流河道储层物性较好,河口砂坝、席状砂、远砂坝微相次之,湖相泥微相储层物性最差。明确了影响复杂储层成因及质量的地质因素,将多种地质因素运用地质统计学权衡法,建立以砂体毛厚度、有效厚度、储层物性、沉积相带和层间层内非均质性为基础的储层综合评价体系,形成了多参数权衡定量储层套合评价技术,将流沙港组复杂储层进行了综合分类,并对储量动用程度及采收率进行了分析。结合区域的实际情况,提出了适合区域开发的六条建议,为流沙港组复杂储层的开发提供了技术指导和支持。选择了砂岩厚度(H)、有效厚度(He)、微相(facies)、孔隙度(POR)、渗透率(K)、变异系数(Vk)以及夹层密度(F)等8个因子,利用灰色理论灰色关联法对储层进行评分,总共划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ大类,其中对Ⅰ、Ⅱ、Ⅲ各细分为两个亚类,把Ⅱ、Ⅰ2、Ⅱ1、Ⅱ2、Ⅲ1类划为常规储层(有自然产能),而Ⅲ2、Ⅳ类分别为常压地层的非常规储层。综合复杂储层构造建模采用的“Y”字型断层建模技术、地层超覆接触关系处理技术,逆掩断层建模技术以及相建模采用的储层反演技术、趋势面约束相建模技术、井—震—相联合建模技术,形成了一套针对复杂断层和复杂砂体的精细地质建模技术,并且采用地震反演体、沉积微相控制岩性建模,通过饱和度模拟符合实际地质特征,储量拟合误差为7.8%,表明本次复杂储层建模技术优于常规建模技术。综合运用了上述方法和技术,即复杂储层地质评价技术、复杂储层测井-地震联合评价技术、复杂储层综合参数评价技术以及复杂储层三维地质建模技术,形成了一套复杂储层综合评价的流程、方法和技术体系。2011-2013年涠洲11-4N以及涸洲11-1油田的开发中得到了阶段性的应用,且油田的开发调整效果较好。更多还原

【Abstract】 The research on continental oil and gas reservoirs has been more and more delicate, the exploration target of offshore oil-gas reservoir has also been the small sand body, small fault block, complicated reservoir and low permeability reservoir. So the marine oil and gas production will inevitably entered the "complicated reservoir" stage, and meanwhile the corresponding assessment methods, engineering measures and exploration measures should be designed delicately. This paper carries out a study on complicated reservoir sedimentology and integrated assessment of Liushagang formation in weixinan depression(weizhou11-4N,11-1, weizhou11-IN, weizhou11-2,) based on the reservoir forming process and3D varying pattern, established complicated reservoir assessment system and specific methods which can provide the basic rule for the design of reservoir development scheme and adjusted scheme.This dissertation have reconstructed the sequence stratigraphic framework of complicated tectonic-sedimention, and revealed the controlling factors of the complicated sedimentary system using seismic data, core data, logging data, production test and dynamic analysis of well production comprehensively based on sequence stratigraphy, sedimentology, reservoir geology, logging geology and other discipline theories. Additionally, we make a further division of the sedimentary micro-facies of the key strata, analyzes sand body vertical stacking pattern, connectivity and the plane distribution laws, establish the empirical formula between thickness and width of different sand types in different depositional system and the macroscopic heterogeneity parameters. At the same time, this dissertation also analyzes the relationship between the reservoir physical properties, effective reservoir and sedimentary micro-facies systematicly, determines favorable area, and evaluates and classifies the reservoir quantitatively using geo-statistical method. Finally this research establishes a complicated reservoir geological model in the field scale by the means of random3D geological modeling, representing reservoir structure unit, property unit and the favorable reservoir zone in three-dimensional space, which provides certain basis for the development. Research results and the main ideas can be summarized as follows: We have established the uniform sequence stratigraphic framework of Liushagang formation combining the division of oil group, change of accommodation space, division of the original reservoir of base level cycles, integrating sedimentary sequence, T-R sequence and Cross.T A high-resolution sequence stratigraphy theory, based on seismic, core, well log data. We have recognized2long term cycles,9middle term cycles,24short term cycles in the1member of Liushagang formation, and a long term cycle,5middle term cycles,24short term cycles in the3member of Liushagang formation. At the same time, the target layer is divided into5oil groups,8sets of sand bodies from bottom to top according to the distribution of well location, sand bodies and the results of sequence classification. In addition, there is a low lateral connectivity of sand body and the distribution of sand body are different in each of the oil group, what’s more, the main oil group V oil group is divided into V1and V2two layers.The stable heavy mineral assemblages in the north in the upper1member of Liushagang formation are mainly leucoxene, hematite-limonite, zircon and tourmaline from the development of sand body and the quantitative analysis of heavy mineral, which indicate the sources are mainly from the west, extending from west to east. The stable heavy mineral assemblages in the north in the lower1member of Liushagang formation are mainly tourmaline, leucoxene, zircon and hematite-limonite, and zircon, tourmaline and leucoxene in the south, which indicate the sources are mainly from the southwest, extending from west to east and east to north. The stable heavy mineral assemblages in the3member of Liushagang formation are mainly leucoxene, hematite-limonite, zircon and tourmaline, which indicate the sources are mainly from the southwest.The lithology aspects, the upper1member of Liushagang formation is major composed of fine sand, silt-finestone and siltstone, the mainly sedimentary structure includes trough cross-bedding, tabular cross-bedding, small sand grain bedding, small climb stratification, deformation bedding and horizontal bedding, mainly showing tractive current deposition, gravity deposition also exists locally, however, the middle and lower1member of Liushagang formation is major composed of glutenite, conglomeratic sandstones, middle-course sandstones, laminar fine-siltstone and mud stone, the mainly sedimentary structure includes trough cross-bedding, tabular cross-bedding, mixed bedding. On the other hand, the3member of Liushagang formation includes trough cross-bedding, tabular cross-bedding, massive bedding, bioturbation structure.The upper1member of Liushagang formation logging facies can be divided into box type, bell type, funnel-shaped type, finger type and linear type through the detail core description. The middle and lower1member of Liushagang formation logging facies can be further divided into box-funnel combination, bell-bell combination, funnel-finger combination, box-box combination and box-finger combination. The upper1member of Liushagang formation can be identified as normal delta front deposition based on the core analysis and logging facies, the delta inner-front can be further divided into braided channel, mouth bar, sheet sand, inter-channel, and the delta exo-front can be further divided into branch channel, mouth bar, distal bar, sheet sand, inter-channel. The lower1member of Liushagang formation can also be divided into delta inner-front and exo-front, further divided into8microfacies. The upper3member of Liushagang formation can be identified as delta exo-front, including4microfacies, the lower part is identified as delta inner-front including5microfacies, the delta inner-front can be further divided into braided channel, mouth bar, sheet sand, inter-channel, and the delta exo-front can be further divided into branch channel, mouth bar, distal bar, sheet sand, inter-channel.The sandstone superimposed structure is established and divided into6categories,8classes, including braided bar-braided bar pattern, braided bar-braided channel pattern, braided channel-braided channel pattern, branch channel-branch channel pattern, branch channel-mouth bar pattern, branch channel-sheet sand pattern. In the normal delta facies, the average thickness of mouth bar, distributary channel and distal sand are3.4m,3m,1.9m, respectively, the average width of mouth bar, distributary channel and distal sand are296m,294.8m,207.1, respectively, the average width-to-thickness ratio of mouth bar, distributary channel and distal sand are100.9,110.7,115.9, respectively. In the braided river delta, the average thickness of mouth bar, distributary channel are4.2m,6.3m, respectively, the average width of mouth bar, distributary channel are350.9m,348m, respectively, the average width-to-thickness ratio of mouth bar, distributary channel are84.3,70.3, respectively. In the fan-delta, the average depth of braided channel, braided bar, branch channel, mouth bar are3.6m,4.3m,4.1m,2.7m, respectively, the average width of braided channel, braided bar, branch channel, mouth bar are646.1m,783.2m,748.3m,683.9m, respectively, the average width-to-thickness ratio of braided channel, braided bar, branch channel, mouth bar are223.2,242.2,253.7,606.3, respectively.We have analyzed the changing law of physical properties. The results show that porosity ranges from12%to18%, permeability ranges from24md to294md, with regard to reservoir properties, the braid-channel and distributary channel are the best, concentrating around the wells WZ11-1-A5_WZ11-1-2_WZ11-1-A10_WZ11-1-A8. We find it that porosity and permeability in braid-channel has positive rhythm characteristics, however, the mouth bar shows inverse rhythm characteristics, the highest penneability variation coefficient concentrates around well WZ11-1N-2and WZ11-1N-A, the average permeability variation coefficient is about2.4, indicating strong heterogeneity.The log-seismic technique is introduced to track the sand distribution detailly, we find it that the normal delta deposition sand of upper1member of Liushagang formation in the seismic profile shows poor continuity, isolated or banded distribution, on the contrast, the fan-delta front sandbodies of the middle and lower1member of Liushagang formation are mainly composed of conglomerate and coarse sandstone with a large sedimentary thickness. The deposition is manifested as interbeds between thin braided channel deposition and relatively thick mudstone in the canal. There are12sand body developing in3member of Liushagang formation, showing moderate-strong amplitude, high continuity. We can conclude that the sand bodies in the north which is near the provenance are larger and fewer, however, the sand bodies in the south which is far away from the provenance are smaller and richer. We have evaluated the complicated reservoir parameters comprehensively combined with the measured data and logging data. This dissertation has established porosity interpretation model using density and neutron logging data, and established the relationship between porosity and permeability according to the grade above or below the medium sand. We have divided the flow unites into4categories using RQI and Oz combined with578test data in6wells, and established the permeability interpretation models according to the different flow units. The results show that the correlation coefficient in each permeability interpretation model is above0.8under the control of the flow units. By studying the reservoir parameters, we conclude that the good lithology of reservoir of Liushagang formation is coarse sandstone. The coarse sandstone are mainly high permeability reservoir and the fine-grade sandstone (siltstone) is mainly low permeability reservoir. The reservoir is mainly high and medium permeability in general. The lower limit of porosity and permeability are14%,2md, respectively, and upper limit of ash content (Vsh) is15%. And generally the sensitivity of Liushagang formation showed no speed-sensitive or weakly speed-sensitive, weak-acid sensitivity, weak-stress sensitivity, the speed-sensitive are mainly due to the particle size of kaolinite and pore throat match, only individual samples show strong stress-sensitivity and strong acid-sensitivity.We have proposed different testing systems according to different reservoir physical properties based on the analysis of existed complicated reservoir testing system of Liushagang formation, and compiled a set of program to calculate reasonable testing time. We have also analyzed the effect of starting pressure gradient and stress sensitive of permeability to the productivity, and proposed a reasonable method to predict the productivity of the region based on the comprehensive understanding of regional reservoir. Finally, we consider that the test method-"on-off’can best fit the low permeability reservoir of Liushagang formation, and it can achieve high yield only when the porosity is greater than17%, and specific productivity index is also increasing with the increase of permeability, so this further demonstrates that permeability is an very important factor to the productivity of the oil well, we should take a full consideration on the permeability. The relationship between productivity-buried depth and productivity-sedimentary of the complicated reservoir showed that the reservoir with abnormal high pressure has a better productivity at the same depth, distributary channel has the best property, then the mouth bar, sheet sand, distal sand, and the worst is mud.We have been clear about the geological factors affecting the complicated reservoir formation and quality, established the reservoir comprehensive evaluation system based on effective thickness, reservoir property, sedimentary facies zone, and the inter formational and internal heterogeneity, formed a comprehensive multi-parameter weighed quantitative evaluation technique. Meanwhile, the complicated reservoir of Liushagang Formation is classified, and the producing degree of reserves and recovery rate are also analyzed. Eight factors, including sandstone thickness(H), effective thickness (He), micro-facies (facies), porosity (POR), permeability(K), coefficient of variation (Vk), interlayer density (F), are introduced to classify reservoir using grey theory and grey relation method based on the actual regional situation, we divides the reservoir into Ⅰ,Ⅱ,Ⅲ,Ⅳ classes, and Ⅰ,Ⅱ,Ⅲ classes are subdivided into2subclasses, respectively. In addition, the1-1,1-2,Ⅱ-1, Ⅱ-2, Ⅲ-1are classified as conventional reservoir (a natural productivity), and Ⅲ-2, IV are unconventional reservoir in normal pressure formation. These recommendations provide technical guidance and support for the development of complicated reservoir of Liushagang Formation.We have integrated the structural modeling technique of complicated reservoir, including the "Y"-shaped fault modeling technique, the stratigraphic contact relationship processing technique, overthrust fault modeling techniques and the facies modeling technique, including reservoir inversion technique, trend surface modeling technique, well-seismic-facies technique, then the technique for complicated reservoir is established. In addition, the seismic inversion, sedimentary micro facies was used to control lithology modeling, and porosity, permeability, saturation and lithofacies simulation are more likely in accord with the actual geological features, the reserves fitting error is about7.6%, indicating that the complicated reservoir modeling technique is suitable for complicated reservoir and complicated fault block, and the accuracy of modeling is high, it can also reflect the underground structure and sand body structure more precise, and is better than the conventional modeling technique.The process, methods and technique system of complicated reservoir is established using all the methods and technique above, including geology assessment technique, logging-seismic assessment technique, integrated parameters assessment technique and3D geological assessment technique. The integrated assessment technique has been used in WZ11-4N and WZ11-1oilfield during2011-2013, and the effects of development adjustment is better.更多还原