Fault Interior Structure Index Construction and Quantitative Seismic Interpretation of Fault Facies

Fault zones have always drawn attention from the industry,and the performance of a quantitative interpretation of the fault interior structure on seismic data has remained as a big challenge.In this work,we focus on quantitatively populating the heterogeneity of the fault interior structure in a three-dimensional space on seismic data.To realize this goal,we take the South Wuerxun sub-depression in Hailar Basin as an example of a faulted basin.First,based on a heterogeneity analysis using the drilling and logging information from wells,we establish fault zone geologic models and perform seismic forward modeling to determine the relationship between different fault zone models with different fault dips,internal fillings,and P wave responses.Next,the fault interior structure index(FIS)is constructed,and the response features on the FIS from the fault facies and the host rock are observed.Finally,the FIS is applied to perform the quantitative interpretation and prediction of the heterogeneity in the FIS on seismic data.The results show that the FIS response from the fault zone is higher than that of the host rock in plane,indicating that the former is quantitatively separated from the surrounding host rocks.The FIS values greater than 26 represent the feedback from the fault facies,whereas those less than 26 represent the response from the host rocks.The FIS shows segmented features in the strike,banded in dip on plane.On the slip surface,the FIS indicates the shale smear zone and the location where low-graded and small-scaled faults are densely developed.The heterogeneity prediction result is proven by oil and gas exploration activities.The study results imply that the FIS could indicate a favorable path of the hydrocarbon migration in the fault zone and evaluate the fault sealing parts.The method can explore the quantitative characterization of fault facies and has essential popularization and application values in similar geological application fi elds,including hydrocarbon exploration,development of faulted reservoirs,and geological engineering evaluation related to faults.

Neoproterozoic Molar-tooth Structure and Constraint of Depositional Facies and Environment in the North China Platform in Jiangsu, Anhui and Liaoning, Eastern China

Molar tooth structure （MTS） represented by complex ptygmatical shapes is widely distributed in the Proterozoic of the world. MTS filled by fine, equant sparry calcite （or dolomite） displays an abrupt contact with hosting rocks, which are mainly composed of carbonaceous micrites and fine-grained carbonates with local silts and stormdominated deposits with graded, cross or wave beddings, numerous erosional surfaces and truncated and fills or guttered bases. Occurrence of MTS suggests a result of the constraint of sedimentary facies, and the storm-base in ramp settings is the maximum depth for the formation of MTS. Vertical succession of MTS-bearing carbonates shows a deposition stacked by high-frequency shallow subtidal and peritidal cycles. An individual cyclic MTS-bearing sequence is characterized by thinning, shallowing and dynamic decreasing-upward, and peritidal caps of purple red iron and organic carbonaceous sediments with more complicated shapes of MTS are common on the top of individual MTS-bearing sequences.

Main controlling factor and mechanism of gas-in-place content of the Lower Cambrian shale from different sedimentary facies in the western Hubei area, South China

The Lower Cambrian shale gas in the western Hubei area,South China has a great resource prospect,but the gas-in-place(GIP)content in different sedimentary facies varies widely,and the relevant mechanism has been not well understood.In the present study,two sets of the Lower Cambrian shale samples from the Wells YD4 and YD5 in the western Hubei area,representing the deep-water shelf facies and shallowwater platform facies,respectively,were investigated on the differences of pore types,pore structure and methane adsorption capacity between them,and the main controlling factor and mechanism of their methane adsorption capacities and GIP contents were discussed.The results show that the organic matter(OM)pores in the YD4 shale samples are dominant,while the inorganic mineral(IM)pores in the YD5 shale samples are primary,with underdeveloped OM pores.The pore specific surface area(SSA)and pore volume(PV)of the YD4 shale samples are mainly from micropores and mesopores,respectively,while those of the YD5 shale samples are mainly from micropores and macropores,respectively.The methane adsorption capacity of the YD4 shale samples is significantly higher than that of the YD5 shale samples,with a maximum absolute adsorption capacity of 3.13 cm^(3)/g and 1.31 cm^(3)/g in average,respectively.Compared with the shallow-water platform shale,the deep-water shelf shale has a higher TOC content,a better kerogen type and more developed OM pores,which is the main mechanism for its higher adsorption capacity.The GIP content models based on two samples with a similar TOC content selected respectively from the Wells YD4 and YD5 further indicate that the GIP content of the deep-water shelf shale is mainly 34 m^(3)/t within a depth range of 1000—4000 m,with shale gas exploration and development potential,while the shallow-water platform shale has normally a GIP content of<1 m^(3)/t,with little shale gas potential.Considering the geological and geochemical conditions of shale gas formation and preservation,the deep-water shelf facies is the most favorable target for the Lower Cambrian shale gas exploration and development in the western Hubei area,South China.

Magnetic Structure of Archean Kongling Group from Yangtze Craton,South China

Densities and various magnetic parameters (susceptibility, saturation magnetization, saturation isothermal remanent magnetization and intrinsic coercivity) were measured for 20 representative rock samples of different lithologies from the Archean Kongling amphibolite to granulite facies terrain of the Yangtze craton. Metasedimentary rocks and tonalitic trondhjemitic granodioritic granitic (TTGG) gneisses show that values of susceptibility κ and saturation isothermal remanent magnetization SIRM are higher than those of amphibolites and gabbros. The felsic gneisses have averages of κ =(1 163±375)×10 -6 SI, SIRM =(18.23±8.38) A/m and R 1=0.083 3± 0.005 7 and the metasedimentary rocks κ =(1 236±823)×10 -6 SI, SIRM =(20.70±10.91) A/m and R I=0.071 4±0.025 2. In contrast, mafic rocks have average κ =(764±316)×10 -6 SI, SIRM = (10.46±3.94)A/m and R 1=0.036±0.009 4, and are dominated by a mixed paramagnetic and ferrimagnetic behavior. Thermal magnetic analyses indicate that magnetite and maghemite of low coercivity are the major carriers of remanent magnetism in the metaclastic sedimentary rocks and TTGG gneisses. The amphibolite and gabbro contain minor amounts of magnetite and pyrrhotite. Magnetism of metaclastic sedimentary rocks and TTGG gneisses is highly heterogeneous; variation coefficients of κ and SIRM are as high as 67 % and 53 % for the former and 32 % and 46 % for the latter. Mineral compositions suggest that biotite may be responsible for the higher magnetism of the metasedimentary rocks. The highest variations in κ, SIRM and R I exhibited by metasedimentary rocks can also be interpreted by their largest absolute variations in biotite mass fraction relative to mafic rocks and felsic gneisses. The average ratio ( Q ) of natural remanent magnetization to induced magnetization of felsic gneisses and metasediments is 0.47 . Ratios ( REM ) of natural remanent to saturation isothermal remanent magnetization ranges between 0.000 001 and 0.027 000 and averages 0.002 540. These values are comparable to those of rocks of similar lithologies from the Archean Taihua high grade terrain of the North China craton and from the Ivrea zone, northern Italy. The dominant phase of magnetism carried by the Kongling rocks is suggested to be thermal remanent magnetization. Consequently, high temperature metamorphism exceeding the Curie point of magnetite (585 ℃) might be responsible for the formation of rock magnetism of the exposed crust in the area of investigation.

The Analysis of Seismic Data Structure and Oil and Gas Prediction

In this paper, a new concept called numerical structure of seismic data is introduced and the difference between numerical structure and numerical value of seismic data is explained. Our study shows that the numerical seismic structure is closely related to oil and gas-bearing reservoir, so it is very useful for a geologist or a geophysicist to precisely interpret the oil-bearing layers from the seismic data. This technology can be applied to any exploration or production stage. The new method has been tested on a series of exploratory or development wells and proved to be reliable in China. Hydrocarbon-detection with this new method for 39 exploration wells on 25 structures indi- cates a success ratio of over 80 percent. The new method of hydrocarbon prediction can be applied for: (1) depositional environment of reservoirs with marine fades, delta, or non-marine fades (including fluvial facies, lacustrine fades); (2) sedimentary rocks of reservoirs that are non-marine clastic rocks and carbonate rock; and (3) burial depths range from 300 m to 7000 m, and the minimum thickness of these reservoirs is over 8 m (main frequency is about 50 Hz).

Comparison of the Pore Structure of Ultralow-Permeability Reservoirs Between the East and West Subsags of the Lishui Sag Using Constant-Rate Mercury Injection

In this study, the differences in reservoir parameters, such as pore radius, throat radius, and pore-throat ratio, between the east and west subsags of the Lishui Sag are analyzed by using data obtained from a constant-rate mercury injection experiment. Furthermore, the quality of the reservoirs in the two subsags is systematically evaluated. Results show that the throat radius of the Lishui west subsag is larger than that of the east subsag, and this parameter has a positive correlation with reservoir quality. However, the pore-throat ratio of the east subsag is larger than that of the west subsag, which has an inverse relationship with reservoir quality. The main reasons for this reservoir difference can be attributed to sedimentation and diagenesis. The sedimentary facies types of the Lishui east subsag are the fan delta, shore lake, shallow lake, and shore shallow lake;their sandstone composition maturity is low;the clay mineral content is high;and the rock has undergone strong diagenesis. Therefore, the physical conditions of the reservoir are poor. However, the sandstones in the Lishui west subsag have weak cementation and compaction, mainly with an intergranular pore structure type, which leads to good connectivity between pores. Therefore, the storage performance and seepage capacity of the Lishui west subsag are better than those of the east subsag;the west subsag is the main area of oil and gas accumulation, as confirmed in the process of exploration and development.

Reservoir Rock Facies──Case Presentation of Sandstone Type

The reservoir rock facies is presented by its principal indieators to show the aspects of sedimentary facies,diagenetic change and oil-gas indication. These indicators used by the author are 1) the petrologic──of which the sedimentary facies and vitrinite reflectance are included, 2) the physical ── pore/throat di-ameter ratio and coordination number of throat connecting pore, and 3) the geochemical──photochemical parameters of individual organic inclusion. Based on the above mentioned quantitative indicators,the defined reservoir rock facies may not only be used for itself evaluation, but also may be put in facies column or facies-palaeogeographic map to predict or to trace oil-gas reservoir. Microscope photometry,micro-FT-IR and Laser Raman methods were used for studying all the aforesaid parameters by means of thinned polished sections from core or cemented cuttings, except the 3-D others, from parallel and vertical to bedding or some duplicate core samples, that the rose fluorescein preparation must be soaked in for the convenience of studying pore throat structure.

Magnetic Structure of Continental Crust: Implications for Crustal Structure and Evolution

Magnetic structure of the continental crust is one of the important geophysical aspects of continental lithosphere. This paper reviews the achievements in the research into the magnetic structure and its significance for crustal tectonics, composition, metamorphic facies, crust mantle interaction and magnetization of deep crust. Further studies are suggested according to the basic principles of rock and mineral magnetism in terms of petrology, geochemistry and structural geology. Emphasis is placed on new geological ideas and synthetic studies of the relationship between deep geological processes and interpretation of gravity, magnetic, electrical and seismic data. The relationships between magnetic, density, electricity, velocity, geothermal structures and deep geodynamic processes are taken as a system for the research into the deep geology.

Distribution Prediction of Middle-deep Lacustrine Source Rocks in Eocene Wenchang Formation in the Kaiping Sag,Pearl Mouth Basin

Oil and gas shows are rich in drilling wells in Kaiping sag,however,large oilfield was still not found in this area.For a long time,it is thought that source rocks were developed in the middle-deep lacustrine facies in the Eocene Wenchang Formation,while there is no source rocks that in middle-deep lacustrine facies have been found in well.Thickness of Wenchang Formation is big and reservoirs with good properties could be found in this formation.Distribution and scale of source rock are significant for further direction of petroleum exploration.Distribution characterization of middle-deep lacustrine facies is the base for source rock research.Based on the sedimentary background,fault activity rate,seismic response features,and seismic attributes were analyzed.No limited classification method and multi-attributes neural network deep learning method were used for predicting of source rock distribution in Wenchang Formation.It is found that during the deposition of lower Wenchang Formation,activity rate of main fault controlling the sub sag sedimentation was bigger than 100 m/Ma,which formed development background for middle-deep lacustrine facies.Compared with the seismic response of middle-deep lacustrine source rocks developed in Zhu I depression,those in Kaiping sag are characterized in low frequency and good continuity.Through RGB frequency decomposition,areas with low frequency are main distribution parts for middle-deep lacustrine facies.Dominant frequency,instantaneous frequency,and coherency attributes of seismic could be used in no limited classification method for further identification of middle-deep lacustrine facies.Based on the limitation of geology knowledge,multi-attributes of seismic were analyzed through neural network deep learning method.Distribution of middle-deep lacustrine facies in the fourth member of Wenchang Formation is oriented from west to east and is the largest.Square of the middle-deep lacustrine facies in that member is 154 km^(2)and the volume is 50 km^(3).Achievements could be bases for hydrocarbon accumulation study and for exploration target optimization in Kaiping sag.

碳酸盐岩强非均质储层相控反演方法研究

岩溶缝洞体是碳酸盐岩主要储层类型,具有强非均质性特征,量化预测难度大。常规地震反演方法虽然可实现储层的量化预测,但满足不了岩溶缝洞体中多类型储层的量化及高精度研究需求。针对这一问题,在相控约束反演技术思路的基础上,提出了基于梯度结构张量属性约束的确定性相控反演方法。该方法可概述为3步:首先,基于梯度结构张量属性,划分出反映碳酸盐岩缝洞体轮廓的储层相与非储层相;其次,以地震相为约束条件,建立低频模型;最后,将低频模型应用于地震反演过程,得到储层敏感属性,进而实现碳酸盐岩强非均质储层的量化预测。模型试算结果和塔里木盆地M工区实际应用结果均表明,该方法能有效识别岩溶缝洞体中多类型储层的分布范围,与实钻结果及开发动态特征吻合,为碳酸盐岩缝洞型油藏的整体量化研究奠定了基础。

演武地区延8段储层微观孔隙结构特征及成因

鄂尔多斯盆地演武地区侏罗系延安组是主要的含油气层,为明确该区储层复杂多样的孔隙结构特征及成因,运用精细岩心描述、铸体薄片鉴定、阴极发光、扫描电镜和高压压汞分析等技术,对侏罗系延8段储层微观孔隙结构特征进行详细表征,并综合分析了宏观沉积作用、微观成岩作用对孔隙结构的双重控制。结果表明:延8段储层岩性主要为长石石英砂岩,孔隙度平均为13.99%,渗透率平均为177.33×10^(-3)μm^(2),孔隙类型主要为残余粒间孔和粒间溶孔,孔隙结构以中孔中细喉道为主,属于低孔中渗透储层。储层物性平面上受沉积相带的控制,垂向上明显受成岩作用的影响。不同成岩相储层孔隙结构差异明显:压实胶结相和含铁碳酸盐胶结相绝大多数孔隙和喉道被假杂基化的塑性颗粒或碳酸盐胶结物充填,孔隙类型主要为残余粒间孔,孔隙结构类型以小孔细喉道为主,物性较差;强溶蚀相和自生石英-长石弱溶解相次生溶孔发育,储层物性得到改善,孔隙连通性好,孔隙结构类型以中孔粗喉道为主,是油气富集的有利相带。

Fe_(2)O_(3)对高硅碱性球团固结性能的影响

深入研究Fe_(2)O_(3)对于高硅碱性球团生球以及成品球性能的影响,有助于促进基于我国铁矿资源特征的低碳炼铁技术发展。本文通过调整碱性球团用混合料中Fe_(2)O_(3)的含量,解析Fe_(2)O_(3)对高硅碱性球团生球、预热球和成品球性能的影响规律,并采用扫描电镜以及图像识别处理系统表征高硅碱性球团的微观矿相结构。结果表明:随着混匀矿中赤铁矿配比的提高,高硅碱性球团生球、预热球和成品球的抗压强度均有所降低,随着Fe_(2)O_(3)配比的升高,成球性能劣化,生球的抗压强度降低至9.04 N/P。赤铁矿连晶固结性能变差,成品球的强度降低至3433 N/P。当两种矿粉的配比为50%时,球团孔隙率急剧增大为32.8%,A矿粉配比不宜超过40%。微观矿相结果表明,随着Fe_(2)O_(3)含量的增加,球团内部小颗粒尺寸晶粒变多,大颗粒尺寸晶粒减少,平均颗粒面积减少,晶粒间连晶性能变差,固结性能削弱,内部孔隙率提高。在制备高硅碱性球团时,含Fe_(2)O_(3)的精矿粉配加不宜太高,会对球团矿的固结性能产生不利影响。

海陆过渡相页岩孔隙结构表征及页岩气渗流规律模拟

鄂尔多斯盆地大宁-吉县区块海陆过渡相页岩储层非均质性强,碳质页岩和纯页岩的孔隙结构特征及页岩气渗流规律具有明显的差异,然而目前针对不同岩性孔隙结构下的页岩气渗流规律研究较为缺乏。文中以这2种岩性页岩为研究对象,基于CT扫描、扫描电镜物理实验技术,测定了二者的基质孔隙和层理缝特征参数,对比了二者的孔隙结构差异,构建了考虑吸附效应和滑脱效应的格子玻尔兹曼数值模拟方法,分析了二者孔隙结构对页岩气渗流规律的影响。研究结果表明:1)碳质页岩裂缝呈空间网状结构,纯页岩裂缝为平行层理方向裂缝。与纯页岩相比,碳质页岩孔隙尺度较大,但孔隙数量较少,孔隙度更低。2)页岩孔隙中存在明显的滑脱效应。滑脱效应提高了气相流动速度,页岩气从孔隙壁面解吸减缓了孔隙压力降低速率,延长了生产时间。建议在开发纯页岩层段时,适当降低生产压差,增强小孔隙中的滑脱效应;在开发碳质页岩层段时,适当增加生产压差,通过解吸作用提高页岩气产量。

大型红层缓倾岩层滑坡形成机制——以川北断渠滑坡为例

大型缓倾岩层滑坡在红层地区广泛分布,由于滑前迹象不明显,很难做到早期防范。为了探索此类滑坡的风险斜坡判识和早期识别,以四川北部南江县断渠滑坡为例,从孕灾地层沉积相和岩性组合特征、区域地质构造演化和层间剪切带发育特征等角度,分析了该滑坡的形成机制。该滑坡体积约为1153×10^(4)m^(3),主滑方向总体向南(170°),为一特大型缓倾岩层古滑坡。滑坡发育于侏罗系中统沙溪庙组上段和沙溪庙组下段交界部位,是岩性和岩相的转换面。沉积相的组合特征决定了斜坡上硬下软的坡体结构。滑坡位于四川盆地北缘新华向斜北西翼,受到了多期地质构造作用,米仓山南缘前陆盆地盖层底部楔入冲断构造模式产生了上部地层原地掀斜效应,增加了层间机械破碎作用,并且软硬2个系列地层交界处应力更易集中,在孕灾地层上下厚度约80 m范围内共计发育了数10条层间剪切带。在地下水大量参与下,破碎程度高且原岩含大量黏土矿物的层间剪切带被逐渐泥化,为滑坡下滑提供了力学条件。

海陆过渡相煤系页岩孔隙分形特征及影响因素——以沁水盆地北部太原组为例

【目的】为分析沁水盆地北部太原组海陆过渡相煤系页岩孔隙分形特征及影响因素。【方法】通过对阳泉区块太原组样品进行总有机碳(TOC)含量、成熟度测试及X射线衍射、低温氮气吸附实验,基于(Frenkel Halsey Hill,FHH)理论模型计算样品孔隙分形维数,分析矿物含量、有机地化特征及孔隙结构参数对孔隙分形维数的影响。【结果】太原组煤系页岩TOC含量介于0.57%~6.40%,平均为3.18%;有机质镜质体反射率(R_(o))介于1.96%~3.24%,平均为2.49%;煤系页岩微观孔隙具有双重分形特点,其中表面分形维数(D_(1))介于2.507 9~2.663 9,结构分形维数(D_(2))介于2.527 1~2.809 4;有机质含量及成熟度与D_(1)、D_(2)均呈正相关关系,孔隙结构参数与D_(1)、D_(2)具有良好的正相关性,但与D_(2)相关系数高于D_(1),指示微孔对孔隙结构参数的影响更强;分选、磨圆度高的陆源碎屑石英多具规则孔隙形态,造成石英含量与D_(1)、D_(2)呈负相关关系;碳酸盐岩矿物及长石主要提供宏孔,其含量与页岩D_(1)及D_(2)均呈负相关关系;黏土矿物在长期压实作用下孔径减小,微孔数量增加,孔隙形态复杂,其含量与分形维数D_(1)及D_(2)呈正相关关系。【结论】海陆过渡相煤系页岩微观孔隙具有双重分形特点,有机质含量、成熟度、孔隙结构参数和黏土矿物含量增大可导致其微观孔隙分形维数变大,陆源碎屑石英、长石和碳酸盐矿物含量增多可导致其微观孔隙分形维数变小。

南堡4号构造东营组岩石物理相特征及其分类评价

南堡凹陷4号构造晚期成岩作用强烈、储层非均质性强、孔隙结构复杂,导致优质储层岩石物理特征不清及储层有效性评价难.针对这一难题,综合利用岩心薄片鉴定、扫描电镜、X全岩衍射、毛管实验及测录、试油等数据对储层的沉积特征、成岩特征及孔隙结构特征开展相控研究,研究结果表明研究区东二、东三段沉积相主要发育辫状河三角洲相,沉积微相主要发育水下分流河道、分流间湾、河口坝等;依据成岩作用及矿物类型将成岩相划分为弱溶蚀相、黏土矿物充填相、碳酸盐胶结相、压实致密相四类;根据储层物性及压汞等数据将孔隙结构相划分为Ⅰ类大孔粗喉型、Ⅱ类大孔中喉型、Ⅲ类中孔细喉型、Ⅳ类小孔微喉型.基于沉积、成岩、孔隙结构三种特征单元叠加聚类分析将储层岩石物理相划分为PF1-PF4四类,其中PF1为油气及油水产能高的优势储层,PF2为产能一般的含油储层,PF3为需要储层改造才有产能的较差储层,PF4为无效储层,通过测井响应规律建立岩石物理相分类评价标准,为研究区储层有效性评价、优势储层预测以及后续的滚动开发提供了技术支撑和坚实的理论基础.

四川盆地公山庙西地区侏罗系大安寨段致密油储层特征及高产主控因素

在致密灰岩储层特征认识的基础上,利用薄片鉴定、测井响应、叠前地震波形指示反演(SMI)等方法对四川盆地公山庙西地区大安寨段致密灰岩储层特征及高产主控因素展开了详细研究。研究结果表明:①四川盆地公山庙西地区大安寨段灰岩储层可分为厚层型和薄层型2种类型。灰岩储层平均孔隙度为1.2%,平均渗透率为0.05 mD,为特低孔、低渗储层,储集空间主要为次生溶孔和微裂缝;②根据断层规模、断穿层位及平面上的断距,将研究区断层分为一级、二级和三级,其中大安寨段主要受一级和二级断层影响,与断层伴生的裂缝体系有效改善了储层物性;③研究区有利相带控制了油气的分布,断储配置关系控制了油藏的产能,可分为“薄层灰岩+一级断缝”与“厚层灰岩+一级/二级断缝”2种高产模式。

新疆博格达山北缘二叠纪中—晚期构造运动的沉积响应

博格达山北缘是准噶尔盆地与天山造山带之间的关键部位,是研究盆山关系的重点区域。博格达山北缘二叠纪中、晚期的构造演化与沉积时空演变关系存在较大争议。本研究通过野外实地勘测、镜下岩石薄片鉴定、粒度分析实验和地震资料解析等方法,针对博格达山北缘东、西部两条剖面—大龙口剖面和井井子沟剖面开展研究,分析其沉积类型和演变过程,解析盆山构造变形和发育特征,探讨构造运动的沉积响应。研究结果表明:瓜德鲁普统乌拉泊组为湖成三角洲相,井井子沟组至红雁池组为湖泊相,乐平统泉子街组为冲积扇—河流相沉积,梧桐沟组和锅底坑组为滨浅湖—三角洲相沉积;研究区可分为两个主要构造层,下构造层以伸展断陷为主要结构,上构造层以前陆冲断为主要构造变形;多期构造活动控制瓜德鲁普统、乐平统沉积演化过程,在挤压构造背景下,瓜德鲁普统的湖泊相转变为乐平统冲积扇—河流相沉积,晚期构造活动趋于稳定,区域进入准平原化作用阶段。

页岩气水平井地质建模中几个关键问题处理技术

页岩储层三维地质建模存在若干技术难题,例如基于顺层水平井构造还原及精细建模技术问题、基于水平井的页岩多属性参数一体化建模技术问题及不同尺度天然裂缝综合表征及建模技术问题等,本文就以上几个问题的处理技术进行了探讨。针对基于顺层水平井构造还原及精细建模问题,提出使用水平井段密集分层节点数据全点约束的层面循环构建技术进行处理;针对基于水平井的页岩多属性参数一体化建模技术问题,提出使用相控及多属性约束的逐级关联建模技术,其中由于水平井数据采样产生的统计偏误问题,采用对水平段所在的小层进行高精度分层细化水平段定位及平面网格倍数抽稀的办法进行处理;针对页岩中多尺度天然裂缝综合表征及建模技术问题,推荐采用裂缝分形模拟技术;针对水平井导向模型在钻井中实时更新问题,推荐采用虚拟井分层控制技术方法。以上技术方法均通过威远气田验证,大幅度提高了模型的精度和可靠性,在页岩气储层地质建模中可推广使用。

强冲击地压矿井煤层顶板覆岩结构研究——以孟村煤矿为例

矿井工作面上覆坚硬厚层顶板对冲击地压的产生具有重要影响,顶板坚硬厚层砂岩通常因沉积相的变化在横向和纵向上呈现出厚度、顶底板起伏和岩石力学性质等方面的变化。陕西彬长矿区孟村煤矿地质条件复杂,主采煤层顶板发育多层厚砂岩,矿井长期受冲击地压灾害威胁。为准确掌握工作面顶板坚硬厚层砂体层位及展布状态等信息,对其进行压裂弱化,保障矿井安全高效开采,基于孟村煤矿工程地质条件,通过井下工作面巷道顶板钻孔取心编录和钻孔电视测井方法,进行工作面顶板覆岩结构探查,对顶板主要砂体采样,进行岩石学、沉积相和岩石物理力学性质等特征分析,得到如下主要成果:①孟村煤矿401103工作面顶板100m内可对比划分出5层连续的砂体,工作面沉积微相变化导致各砂体厚度和顶底板标高不稳定;②401103工作面顶板延安组二段、直罗组、安定组底部均为河流相沉积,河流微相中的天然堤相细粒砂岩和粉砂岩的岩石力学强度相对最大,随着岩石粒径的逐渐增大,边滩相和河床滞留相中、粗粒砂岩的强度相对降低。不同沉积环境同一粒级砂岩的岩石力学强度因石英含量增高、硅质胶结物含量增高、颗粒支撑结构等因素而增大;③井田现今构造应力和顶板坚硬厚层砂岩等是矿井冲击地压灾害的主要诱因,对上覆高位坚硬厚层砂体进行区域水力致裂弱化,可显著降低矿井冲击地压风险。