In order to clarify the multi-scale pore and fracture structure characteristics and main controlling factors of coal reservoirs in the Shenmu Jiaxian block on the eastern edge of the Ordos Basin, multiple experiments were conducted, including CT scanning, scanning electron microscopy, high-pressure mercury injection, low-temperature nitrogen adsorption, and low-temperature carbon dioxide adsorption. A multi-scale full aperture development map of coal and rock in the study area was established using the full aperture stitching method, and the reasons for the differences in gas content and pore development between the Shenmu and Jiaxian blocks were explored.The results show that: ① In terms of multi-scale pore fracture characteristics, the study area as a whole has developed cleavage fractures and millimeter scale fractures with parallel or vertical bedding. The total fracture rates in Shenmu and Jiaxian are 7.01% and 6.06%, respectively. The average total fracture rate in Shenmu block is slightly higher, but more than 90% of the fractures are filled with high-density minerals. The storage space types of coal seams in Shenmu block are mainly organized pores, with rare pores and intergranular pores of clay minerals, ranging in size from a few micrometers to several tens of micrometers; The storage space types of coal seams in the Jiaxian block are mainly organized pores and gas pores, with visible intergranular fractures of clay minerals in some areas, with pore sizes ranging from a few nanometers to tens of micrometers, and micro scale fractures developed. ② In terms of the distribution characteristics of the full pore size, the proportion of micropores in both blocks is above 99%, indicating that the coal rock adsorption capacity in the study area is strong. The coal reservoir space in Shenmu block is mainly composed of macropores, with an average proportion of 74.72% for macropores, 23.28% for micropores, and an average specific surface area of 41.24m2/g for micropores; The coal seam storage space in the Jiaxian block is mainly composed of macropores and micropores, with macropores accounting for an average of 64.00%, micropores accounting for an average of 34.85%, and micropores having an average specific surface area of 102.73m2/g. The adsorption capacity of the Jiaxian block is better than that of the Shenmu block. ③ In terms of the analysis of factors affecting gas occurrence patterns, the differences in micro component content and ash content between the two blocks result in different types of pore and fracture development. This is mainly reflected in the high degree of thermal evolution, higher content of vitrinite, more developed pores, and higher specific surface area of micropores with pore widths below 2nm in the Jiaxian block. They have stronger adsorption and hydrocarbon generation capabilities, and both the top and bottom plates are weakly permeable rock types with strong compressive and elastic deformation capabilities. They have good sealing conditions and are more conducive to the preservation of coalbed methane reservoirs. The research provides a theoretical basis for efficient exploration and development of deep coalbed methane in the subsequent study area.

Annular reservoirs with gas cap and edge water face the dual challenges of gas channeling and water invasion during development,requiring timely adjustment of development strategies based on development effect evaluation.The Du X Well Block of Liaohe SG-1 Oilfield is a thin-bedded annular reservoir with gas cap and edge water developed by using natural energy.Rapid reservoir pressure decline leads to premature edge-water encroachment and gas-cap channeling,which adversely affects development efficiency.Through numerical simulation and formula-based method for development scheme comparison,it is found that thin-bedded reservoirs have small pay zone thickness and weak shielding and blocking effect on gas.Compared with water flooding,gas injection is more prone to premature breakthrough and gas channeling,resulting in poor development effect.An innovative water flooding mode is designed,featuring energy supplementation via barrier water injection at the lower part and oil production at the upper part.Injection parameters including injection rate,injection volume,and injection-production ratio are optimized using methods such as critical flow rate analysis and Weng Wenbo' Logistic Cyclical Method.The effects of inhibiting edge-water encroachment,suppressing top gas channeling,and tapping remaining oil potential are investigated.The results indicate that barrier water injection at the lower part effectively improves the block recovery factor by 3.5 percentage points compared with gas drive development and 6.5 percentage points compared with natural energy development.This study provides significant guidance for the efficient development of gas-cap edge-water annular thin-bedded reservoirs.

Multi provenance delta composite channels reservoirs in continental rifted lake basins generally have the characteristics of frequent channel bifurcation, good connectivity and strong heterogeneity. In sparse well patterned reservoirs, traditional hierarchical phase-controlled modeling approaches have limitations in predicting cross-well properties and characterizing strong heterogeneity. The modeling method with “partitioned simulating-trend body constraint-hierarchical facies-controlled” is specially presented, the geometric shape of river sandbody, description of main streamline and geological mapping are concretely highlighted, the partition simulation and coupling of different provenances with minor stratum as the unit are implemented, and the trend body for distance attribute of the overall set of grid constructed by main streamline of the river is used as a variable for constraining. Meanwhile, the model is constructed by hierarchical facies-controlled. The results show that partition simulation and coupling supports further truly reflecting the distribution characteristics of reservoirs controlled by different provenances, and differentially considering the extension direction and scale of the sandbody. The trend body constraint and facies-controlled support further accurately determining the sandbody boundary on the plane and simulating physical property change characteristics of the channel from the center line to the flank under the condition of medium and low well control, characterizing the heterogeneity of continuous channel sandbody in more precise manner, and the shape of flat top and convex bottom of the sandbody on the profile and the characteristics of intersection relations are more significant. The research results of remaining oil and flow field on that basis further coincide with the actual situation. Accordingly, comprehensive treatment and flow field regulation were implemented in Nanpu Oilfield, achieving satisfactory field application effects. The above mentioned idea for fine geological modeling of multi-provenance and strong heterogeneity reservoirs starts with basic geological research and mapping, highlighting collaborative constraints and simulations of multi-level and multi-attributes base on sedimentary genesis, delivering reference significance on the studies in similar reservoirs.

To address the problem of unclear main controlling factors of hydrocarbon differential enrichment in the upthrown and downthrown blocks of faults, this paper summarizes the characteristics of differential accumulation in the two blocks of Nanpu No.1 fault and the influence of different geological factors on the differential accumulation characteristics, compares and analyzes the differences in transport conditions, preservations and trap conditions between the two blocks. The results show that the oil source fault can be further subdivided into two stages based on the spatial contact relationship with hydrocarbon source rock and trap. The difference in transmission capacity of different faults in the upthrown and downthrown blocks determines the difference in enrichment degree between the two blocks; the difference in preservation conditions determines the difference of enrichment layers between the two blocks, and the difference in the relationship between traps and different levels of transport fault combination determines the difference of accumulation positions in the two-block. It can be concluded that the downthrown block of the fault can be summed up as “two-way hydrocarbon supply and fault anticline accumulation” for the first-order transport faults on both sides, and the “one-way hydrocarbon supply and fault-block accumulation” mode for the downthrown. The research results can provide a reference for rolling exploration in similar blocks.

The Guantao Formation is the most important reservoir with significant faces developed, and this is different from the near-source accumulation of Nanpu sag. Guantao Formation in Matouying Uplift was found far away from the source area, which is a typical accumulation outside sources. What is the difference on accumulation condition and main controlling factors between the far-source accumulation and near-source accumulation? And what is the reasonable explanation for these reservoirs? According to the main controlling factors of Guantao Formation reservoir in Matouying Uplift, the abundant accumulation in hydrocarbon generation sag, efficient transport system and good spatial and temporal configuration of reservoir cap rock are the main controlling factors for its hydrocarbon accumulation outside sources. The hydrocarbon movement follows a migration model when it passes through a multiple faulted terrace zone and an effective connection to faults has an increase in the hydrocarbon abundance. The determination of oil sources and the correct understanding of the transport system are the keys to the reservoir understanding of the Guantao Formation in Matouying Uplift, as well as to the establishment of the reservoir model and the prediction of favorable oil and gas development areas. It provides enlightenment for the exploration of reservoir outside sources in peripheral convex and although oil and gas displays have been seen during single-well drilling, no large-scale reservoirs have been discovered until the industrial flow of oil and the results enrich the future exploration trend and potential areas in the uplift around the Nazione and Npu sag are determined.

The pore-throat structure of low- to ultralow-permeability reservoirs is complex, causing the permeability to vary greatly under similar porosity conditions. Moreover, the pore-throat structures are the key factors that controled the physical properties of such kind of reservoirs. Therefore, conventional reservoir evaluation methods can hardly meet the research needs of low- to ultralow-permeability reservoir exploration and development. We have conducted our research on Paleogene Shahejie and Neogene Dongying low- to ultralow-permeability reservoirs in the eastern Nanpu Sag of the Bohai Bay Basin to address this issue. Cores, thin sections, and scanning electron microscopy were used to analyze the pore-throat structures to determine the characteristics of low- to ultralow-permeability reservoirs, and a new parameter for evaluating low- to ultralow-permeability reservoirs is developed. The results of this research show that primary pores, secondary pores, and microfractures are developed in the study area and that the pore-throat shape is mainly flaky or curved flaky. The microscopic pore-throat structure controlled the reservoir physical properties and fluid mobility of these reservoirs, the permeabilities of these reservoirs are dependent on the pore throats, and the correlation between connected pores and permeability is strong. Based on the analysis of the pore-throat structure, as well as the maximum mercury saturation (Smax) and the residual mercury saturation (Sr) at the maximum pressure and the minimum pressure obtained by the mercury injection test, an evaluation of the reservoir by using the mobility parameter of fluid (Δfm = Smax-Sr) is proposed, and the pore-throat radius R15 obtained by the mercury intrusion experiment has the best correlation with the fluid mobility parameters. The mobility parameters of fluid can effectively improve the accuracy of logging interpretation of low- to ultralow-permeability reservoirs and provide a scientific basis for the scale stimulation and effective development of low- to ultralow-permeability reservoirs.

南堡凹陷古近系东营组/沙河街组(Ed/Es)不整合结构普遍发育,不同区域的发育特征不尽相同,其中南堡凹陷3号构造区就显示出了明显的差异性.综合三维地震、测井曲线、钻井岩芯、物性分析等资料,系统分析南堡凹陷3号构造区Ed/Es不整合结构岩石学、测井响应、物性以及空间分布特征.结果表明:Ed/Es不整合结构可以划分为不整合面之上的岩石、风化黏土层和半风化层3层,其中风化黏土层发育程度较低;不整合结构具有不同的岩石学特征,不整合面之上的岩石风化程度最低,泥质含量高,风化黏土层风化程度高,物性最差,半风化层受改造程度高,物性最好;不整合结构的分布在平面和空间上较为一致,不整合面之上的岩石和半风化层岩石在顺物源方向上较为发育,在垂直物源方向上发育程度较低,风化黏土层在垂直物源方向上中部地区较为发育,在顺物源方向上欠发育;不整合结构发育程度上的非均一性对油气产生不同影响,其中不整合面之上的岩石和风化黏土层主要作为油气的封盖层,半风化层则主要作为油气运移的输导层.

应用高精度层序地层学理论和方法,通过对地震资料新一轮处理和精细解释,结合岩—电响应特征,共识别出南堡凹陷西斜坡中深层4个三级层序界面,划分了3个三级层序(SQ7、SQ8、SQ9).以三级层序内部相对稳定的水进面和岩性突变面为界进行高精度层序地层划分,进一步划分出12个四级层序或体系域的地层单元.在对研究区物源研究的基础上,开展系统的岩心相、测井相精细研究,共识别出扇三角洲和湖泊两种沉积体系.并在高精度层序地层格架内研究了各沉积体系平面展布特征,其中扇三角洲平原分布范围相对较小,主要集中在研究区北部靠近物源口附近;而扇三角洲前缘分布范围较广,主要发育于研究区的中心部位.

南堡凹陷1号构造东营组储层埋藏深,经历了复杂的成岩作用改造,导致储层物性平面上和纵向上分布不均匀.以岩心观察、薄片鉴定、扫描电镜观察为基本手段,结合黏土矿物X-衍射分析、电子探针分析及阴极发光分析,研究了南堡1号构造东营组储层成岩作用类型及特征,划分了成岩演化阶段、成岩演化序列和成岩体系.结果表明,南堡1号构造东营组储层成岩作用包括压实作用、胶结作用、交代作用和溶解作用,主要处于中成岩A1亚期.研究结果为预测优质储层的分布提供了依据.

With consideration to difficulties related to poor understanding to low-amplitude structures of Guantao Formation in the Matouying Uplift, accurate prediction of reservoirs and uncertainties in patterns of reservoir formation, equivalent Q compensation high-resolution processing techniques have been deployed to enhance resolution of master frequency of seismic data with the master frequency in seismic data of target formations increased from 30Hz to 40Hz;By using layer-controlled grid tomographic velocity modeling, accuracy in velocity determined can be enhanced to identify low-amplitude structural traps more accurately;In addition, attribution analysis technologies were used for analyses of sedimentary facies to determine distribution of channel sand bodies in target formations more accurately.In addition, comparison of bio-markers in crude oil, hydrocarbon transmission system and major controlling factors for reservoirs have been analyzed to clarify reservoir-control elements in Guantao Formation of Matouying Uplift.In this way, time-space configuration among different reservoir-formation elements can be highlighted to re-construct reservoir pattern of the Guantao Formation in the Matouying Uplift.In this way, favorable zones with accumulation of hydrocarbons can be identified.Through deployment of exploration operations, desirable performances have been achieved in exploration.At the same time, sophisticated fine assessment technologies and methods for low-amplitude structures in shallow formations have been developed.Relevant research results may provide valuable references for exploration of low-amplitude structural oil reservoirs with similar geologic conditions in surround uplifts of Jidong Oilfield and these in the Bohai Bay Basin.

现有资料对比发现,马头营凸起钻井资料所揭示的地层产状与时间域地震资料上所反映的产状不一致,馆陶组时间域等T0图的构造形态与馆陶组真实的构造形态存在较大差异.面临马头营凸起构造幅度低、砂层薄、油藏类型复杂多变等问题,通过对地震资料进行重新处理,并对不同方法处理的数据体进行相应的解释和分析,然后在精细速度分析的基础上,运用变速成图技术,对马头营凸起低幅度构造进行了重新落实.通过实钻证明,变速成图技术落实的构造形态与真实构造形态吻合度高,构造形态的落实为马头营凸起后期的勘探开发工作提供了技术支撑和准确的参考资料.

岩心观察、薄片鉴定、全岩矿物等测试分析表明，南堡3号构造中深层中低渗储层岩石类型为长石砂岩和岩屑长石砂岩，在碎屑组分中长石含量较高，存在钾长石、斜长石、微斜长石等多种类型，进一步观察发现储层碎屑组分成分成熟度和结构成熟度偏低，为近物源快速堆积。利用铸体薄片及分析化验资料进一步分析了储层微观孔喉特征，结果表明：南堡3号构造中深层储层孔隙以次生孔隙为主，主要为粒间溶蚀孔隙、粒内溶蚀孔隙，喉道主要为片状或弯片状喉道，共发育6种孔喉结构，并以中孔细喉型和小孔细喉型为主，储层类型为中等—差储层，对该储层喉道加以改造，可有效改善储层物性。

在对大量薄片和岩心观察分析基础上,结合扫描电镜和全岩分析、X衍射粘土分析、包裹体测温等手段,对查干凹陷碎屑岩储层的成岩作用和孔隙演化进行了研究.结果表明:研究区碎屑岩储层主要为低成分成熟度、低结构成熟度的长石岩屑砂岩,成岩作用呈现“强压实、强胶结、弱交代、弱溶蚀”的“两强两弱”特征;成岩阶段主要处于中成岩A期,局部达中成岩B期至晚成岩期.两期胶结主要发生在苏二早期和乌兰苏海时期,中浅层(＜2 500 m)较低孔隙度主要由于强压实和早期致密胶结所致;较高孔隙度是由于原生孔隙保存较好,长石及碳酸盐胶结物的溶蚀作用导致孔隙度增大.深层碎屑岩储层(＞2 500 m)较低孔隙度除压实作用外,碳酸盐致密胶结是主因;较高孔隙度则为早期酸性溶蚀叠加晚期碱性溶蚀产生次生孔隙为主.晚期碱性溶蚀发生在油气充注之后,为无效溶孔.

沙三段是南堡凹陷沙河街组主要的烃源岩层之一,认清沙三段的烃源岩特征对于南堡凹陷研究具有重要意义.通过多种评价手段,对沙三段烃源岩有机质丰度、有机质类型和有机质热演化程度进行综合研究可知:林雀次凹有机碳含量最高;热解S1+S2含量主要分布在0.01～75.69 mg/g之间;氯仿沥青“A”含量约为0.149％,总烃含量均值为1 100×10-6;有机质类型以Ⅱ2型为主;烃源岩镜质体反射率主要分布在0.25％～1.75％范围内;生烃高峰深度在4 000m左右.对南堡凹陷沙三段烃源岩特征的落实,为南堡凹陷油气成因的认识、油气的预测和下一步的勘探提供了参考.

以南堡2号构造古近系东营组一段为研究对象，开展东一段沉积微相展布及演化规律研究。通过岩心观察，测井相分析，结合骨架剖面的沉积微相和地震相研究表明，东一段为辫状河三角洲前缘沉积体系，主要发育水下分流河道、河口坝、远砂坝、席状砂和水下分流河道间沉积微相。其中水下分流河道和河口坝砂体等粗岩相与含油性的关系密切，为物性较好的储集相带，伴随着水体变浅，东一段整体上组成了一套向上岩性变粗、泥岩颜色变浅的反旋回沉积，反映了东一段沉积期湖盆不断萎缩、逐渐消亡的过程。该研究对研究区储层的认识和研究区的勘探开发具有一定指导意义。

As the Tertiary source rocks of salt lake facies in west Qaidam basin have relatively low organic abundance and strong heterogeneity,it is difficult to objectively evaluate them with limited laboratory analytical data of core and cutting.Organic geochemistry and logging data are integrated to establish a set of logging evaluation methods which are used to obtain a large amount of evaluation parameters of source rocks.Analysis of these data reveals that mud shale interbeded with halite or chuco and halite-bearing mud shale are quality source rocks with high abundance of organic matter(TOC1.0%) and favorable organic types in the study area.In addition,the patterns of quality source rock distribution in different layers are also analyzed.The E32 quality source rock is the major hydrocarbon kitchen,followed by E31,while the N11 and N12 moderate source rocks are underdeveloped.

There exist three types of over-pressured formations of Paleogene in Dongying sag.The undercompaction and hydrocarbon generation are the genetic mechanism of mudstone overpressure,according to the synthetic compaction curve and pressure forward modeling.The contact transmission leads to the overpressure of type-I sandstone contacting over-pressured mudstone,while the connecting transmission is the cause of forming overpressure of type-II sandstone.It is shown that weak overpressure occurs in mudstone in deeper well interval of Middle Sha-3 member,middle overpressure in Lower Sha-3 member and high overpressure in Sha-4 member.The mudstone pressure center depends on the sedimentary center,so the intensity of overpressure is decreasing toward the basin margin and distributed circularly.There is little overpressure in shallow sandstone less than 3 000 m in depth,except for its part distribution near the fault zone and unconformity,and the overpressure intensity of the sandstone is greater than that of the mudstone.In depth of over 3 000 m,such an intensity of the sandstone is smaller than that of the mudstone.

The study of provenance system includes the clastic composition type and microscopic feature,heavy mineral assemblage, typical element distribution,sands distribution and palaeogeographic framework,etc of Es~3 of Eogene Shahejie formation in Minfeng subsag. The results show that the metamorphic rock,granite pegmatite,mid-basic effusive rock,basic-ultra basic intrusion rock and sedimentary rock are the main types of parent rocks.There exist NES directions of provenance systems in the studied area where obvious differences in the heavy mineral assemblages,the typical element ratio and the rock composition occur,thus forming the inshore submarine fan in the north,the Yong'an delta in the east and Dongying delta in the south.With the stratigraphic younging,the progradational boundaries of sediments appear towards the basin,with the shrinkage of north provenance system.The intersection area of the three directional provenance systems could be favorable prospecting area of turbidites.