Effect analysis of borehole microseismic monitoring technology on shale gas fracturing in western Hubei

Hydraulic fracturing technology is an important means of shale gas development,and microseismic monitoring is the key technology of fracturing effect evaluation.In this study,hydraulic fracturing and microseismic monitoring were simultaneously conducted in the Eyangye 2HF well(hereinafter referred to as EYY2HF well).The target stratum of this well is the second member of the Doushantuo Formation of the Sinian System,which is the oldest stratum of horizontal shale gas wells in the world.A total of 4341 microseismic fracturing events were identified,and 23 fracturing stages of the well were defined.The fluctuation of the number of events showed a repeating“high-low”pattern,and the average energy of these events showed minimal differences.These findings indicate that the water pressure required for the reconstruction of the EYY2HF well is appropriate.The main body of the fracture network extended from northwest to southeast,consistent with the interpretation of regional geological and seismic data.The stimulated rock volumes showed a linear increase with the increase of the fracturing stage.Some technological measures,such as quick lift displacement,quick lift sand ratio,and pump stop for secondary sand addition,were adopted during fracturing to increase the complexity of the fracture network.Microseismic fracture monitoring of the well achieved expected eff ects and guided real-time fracturing operations and fracturing eff ect evaluation.

Fluid migration paths in the marine strata of typical structures in the western Hubei-eastern Chongqing area,China

The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structure and the Jiannan gas field, were selected to analyze biomarker parameters in marine strata and to examine various types of natural gas and hydrocarbon sources. Fluid inclusions; carbon, oxygen, and strontium isotopic characteristics; organic geochemical analysis and simulation of hydrocarbon generation and expulsion history of source rocks were used for tracing fluid migration paths in marine strata of the study area. The Carboniferous-Triassic reservoirs in three typical structures all experienced at least two stages of fluid accumulation. All marine strata above the early Permian were shown to have fluids originating in the Permian rocks, which differed from the late stage fluids. The fluids accumulated in the late Permian reservoirs of the Xinchang structure were Cambrian fluids, while those in the late Carboniferous reservoirs were sourced from a combination of Silurian and Cambrian fluids. A long-distance and large-scale cross-formational flow of fluids destroyed the preservation conditions of earlier accumulated hydrocarbons. A short-distance cross-formational accumulation of Silurian fluids was shown in the late Permian reservoirs of the Longjuba structure with favorable hydrocarbon preservation conditions. The fluid accumulation in the Carboniferous reservoirs of the Jiannan structure mainly originated from neighboring Silurian strata with a small amount from the Cambrian strata. As a result, the Jiannan structure was determined to have the best preservation conditions of the three. Comparative analysis of fluid migration paths in the three structures revealed that the zone with a weaker late tectonism and no superimposition and modification of the Upper and Lower Paleozoic fluids or the Upper Paleozoic zone with the fluid charging from the Lower Paleozoic in the western Hubei-easteru Chongqing area are important target areas for future exploration.

Characteristics of source rocks and paleoenvironment of Lower Silurian Longmaxi Formation in western Hubei

Based on feild outcrop survey,lithology observation and systematic sampling,and with the scanning electron microscope,rock pyrolysis,biomarker compound test and analysis,this paper discussed source rock characteristics and paleoenvironment in western Hubei.The lithology at the bottom of Lower Silurian Longmaxi Formationn in this study area is mainly dark carbonaceous shale,the mineral composition is mostly clay minerals,quartz and feldspar,the content of illite and kaolinite is high,but also contains a minor amount of strawberry pyrite and graptolite fossils.The test and analysishow that the total organic carbon content(TOC)of the source rock is 0.8-6.32%,the average value is 3.42%,and the vitrinite reflectance(Ro)is 1.57-2.95%.The type of organic matter is mainly typeⅡ2.The overall abundance of organic matter is high,and the degree of thermal evolution has reached the stage of high maturity and over maturity.All these have become the good material basis and conditions for the formation of shale gas.The paleoenvironment of the source rocks indicates that the organic matter is a mixed source of planktonic algae and bacteria material.The large amount of hopane also indicates that the bacterial activity is strong during the deposition of organic matter;The water of the ancient lake is almost freshwater and brackishwater in some parts;The redox property of the water is in a strong reduction environment and with a stable stratification,which is also conducive to the preservation of organic matter.The above research results will provide the application of shale gas exploration in western Hubei.

Geochemistry of the Yutangba Se Deposit in Western Hubei, China

The Yutangba Se deposit is a rare high-Se deposit in the world and it is well known for its high contents of Se, which reach 8590×10+{-6} . The ore-hosted rocks are dominated by cherts that have been well developed. Enrichment of selenium in Se-rich ores is obviously controlled by stratigraphic position and lithological character. The closer the rocks are to the Maokou Formation cherts, the more they contain selenium, but in case the stratigraphic horizons are close to one another, the enrichment of selenium would be controlled by lithological character. In the Se ores and abandoned stone coal pile at the Yutangba Se deposit there have been found large amounts of independent Se minerals, for instance, achavalite and a variety of forms of native selenium. Native selenium minerals present in the abandoned stone coal pile are the outcome of a combination of natural factors and anthropologic activities. For example, lime making will create a closed environment favoring the growth of native selenium, and the reduction of selenium will lead to its secondary enrichment. Starting with the study of ore-forming fluids. Systematic studies have been conducted on fluid inclusions separated from the main ore veins in the mining district for their homogenization temperatures, salinities and density, and the results show that fluid inclusions contained in ores from the Yutangba Se deposit are large in number and diverse in form, dominated by primary ones. The homogenization temperatures of two types of fluid inclusions are within the range of {173.2}-{247.5℃}, individually up to 300℃ or even higher; the salinities of fluids in fluid inclusions in quartz and calcite are {5.9%}-{10.1%} and {3.9%}-{4.5%}, respectively; their densities vary from {0.79}-{0.93} g/cm+3. Extensive discovery of Se minerals due to secondary enrichment of selenium in the stone coal provides important clues to the improvements on the metallurgical and recovery technologies for selenium in the black shale series of China, and also is of great significance in expanding selenium reserves and relax the situation of lacking selenium resources on a global scale.

Coordinated development efficiency between cultivated land spatial morphology and agricultural economy in underdeveloped areas in China:Evidence from western Hubei province

Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and agricultural economy(CECA)is of great practical significance to measure the efficiency of cultivated land use,and thereby promote regional rural revitalization.However,few studies to date have focused on coordinated development efficiency between cultivated land use and agricultural economy in mountainous areas from the perspective of cultivated land spatial morphology.Thus,the present study explores CECA with this focus using the data envelopment analysis method,and analyzes the key influencing factors via a geographical detector model in 16 counties in western Hubei province.The results show the following:(1)CECA exhibits significant spatial heterogeneity that is high in the south of the study area and low in the north;(2)scale efficiency is the primary limiting factor for CECA;(3)the insufficient output of cultivated land use mainly restricts CECA in the south of the study area,while individual county in the north suffered from input redundancy and insufficient output;and(4)population density in the southern region has the most significant effect on CECA,and gross domestic product has the greatest impact in the northern region.The results contribute to the derivation of specific measures by which to promote cultivated land use efficiency and sustainable development of the social economy.

Research on the Importance of Monetary Work to the Political Development of the Western Hunan and Hubei Base Areas

During the seven years revolution in the Western Hunan Hubei revolutionary base,currency experienced four stages of construction and development,and became the economic tool of revolutionary regime,and made considerable contribution;however,the importance of politics to financial work is obvious here.Due to the mistakes caused by the left leaning in the revolutionary work,the monetary work in the revolutionary base area in Western Hunan and Hubei has been seriously affected the final result of the influence is to withdraw from the circulation field with the transfer of the main body of the revolutionary team.

鄂西鹤峰埃迪卡拉系灯影组叠层石及其生态环境讨论

【研究目的】扬子区鄂中台地埃迪卡拉系灯影组赋存丰富的叠层石,但尚未有报道对其进行系统描述。通过识别台地西南端鹤峰白果坪剖面灯影组中的叠层石种类、分析沉积环境,阐述古环境对叠层石形态分布的控制,为后续开展鄂中台地埃迪卡拉纪的叠层石研究提供参考。【研究方法】通过剖面测量和镜下观察,于白果坪灯影组白云岩中识别出平直纹层、Stratifera层状、微波状纹层三种层状叠层石和一种Baicalia柱状叠层石。【研究结果】研究认为上述的叠层石类型分别对应周期性暴露(前两种类型)、潟湖(微波状)和潮间带—潮下带上部(柱状)的生态位。对比与白果坪剖面灯影组同期叠层石的形态及分布规律,可知形成叠层石的微生物群落强烈受控于古水深等环境条件。层状叠层石生态区间宽,柱状及其他形态叠层石仅见于局限地区,多样性较低。【结论】扬子区碳酸盐岩台地长期稳定的大范围潮坪环境造成的广泛分布浅水生态位和局限分布较深水生态位,是导致灯影组沉积期叠层石多样性低的主要原因。

鄂西磷矿岩爆现状及治理措施研究

针对鄂西磷矿,在深入调查苏家坡磷矿、麻坪磷矿、桃郁溪磷矿等矿山地质特征及岩爆现象的基础上,分析了鄂西磷矿岩爆灾害主要发生部位、埋深及岩性等影响因素,提出了适合鄂西磷矿岩爆的治理措施:对鄂西地下磷矿进行地应力测试,根据地应力测试结果,优化回采顺序,减少应力集中区域,并在局部区域开展卸压和支护措施,保障井下安全开采。

鄂西—渝东地区上二叠统大隆组页岩气富集条件与勘探有利区

近年来,鄂西—渝东地区多口井在二叠系大隆组获得页岩气重要发现和工业气流,展现出新层系海相页岩气良好的勘探开发前景,深化其地质认识对于指导下一步页岩气勘探具有重要意义。为此,基于岩心观察、薄片及扫描电镜观察、测/录井和有机地球化学数据分析,系统研究了该地区页岩沉积特征、储层特征、有机地球化学特征、含气性和保存条件,明确了大隆组海相页岩气勘探有利区。研究结果表明:①晚二叠世大隆期,该区发育深水台盆相沉积,富有机质页岩发育厚度10~60 m,现今埋深具有盆内埋深大、盆外埋深浅的特征;②大隆组自下而上划分为3段,一段以硅质页岩为主,二段岩性较为复杂,三段以混合质页岩为主,测井响应上表现为高自然伽马、高补偿中子、高声波时差、低电阻率、低密度、电阻率向底部逐渐降低的“三高两低一降”特征;③大隆组页岩脆性矿物以石英和方解石为主,平均值分别为40.58%和23.76%,储集空间分为孔隙(有机质孔、矿物颗粒间孔、粒间溶蚀孔、粒内溶蚀孔)和裂缝(矿物层间缝、有机质与矿物间缝、有机质内裂缝)2大类7种类型,以有机质孔为主,孔径分布呈现“四峰”特征,孔体积集中介于1~10 nm和500~5000 nm两个孔径区间;④大隆组有机质丰度高、储层非均质性强、热演化程度高、有机质类型以Ⅱ1型为主、Ⅱ2型为辅,有机质孔发育;⑤大隆组页岩具有较高的含气量,良好的顶底板条件发挥了重要的封闭作用;盆内受构造抬升剥蚀和断裂影响小,保存条件整体较好,盆外残留向斜核部保存条件较好。结论认为:①大隆组是四川盆地页岩气勘探的新领域,在盆地内发育5个勘探有利区,面积合计5500 km^(2),可加快勘探评价节奏;②在盆外发育7个勘探有利区,面积合计6700 km^(2),应优选残留面积大的有利区开展风险勘探,寻找新的突破和发现。

二叠系大隆组——一个页岩气勘探开发新层系

在百年未有之大变局的新形势下,我国能源发展面临复杂形势和严峻挑战,既要加快推进能源低碳转型实现碳中和目标,又要牢牢守住能源安全底线,这就迫切需要立足国内加大清洁能源勘探开发力度。近10年来,页岩气作为一种低碳清洁能源,成为世界天然气产量增长的主体,深刻改变了全球能源供给格局(赵文智等,2020;邹才能等,2022)。

鄂西宜昌地区寒武系水井沱组页岩储层地应力特征及成因

以四川盆地宜昌地区水井沱组页岩储层为对象,采用钻井实测、岩心测试分析及测井解释等技术,获取多井点现今地应力信息,研究地应力特征,探讨应力差异分布成因。结果表明:宜昌地区水井沱组现今最大水平主应力方向总体为NEE向,东、西部靠近边界断裂的区域呈多向性;现今地应力的离散性较强,平面上呈中部高、东西部低的主体分布特征,纵向上随深度增加而增大;埋藏深度是导致地应力纵向上分布差异的主要因素,三个主应力随埋深呈线性增加,主体区域的应力关系表现为水平最大主应力>垂向主应力>水平最小主应力,属于走滑断层应力状态;不同岩性层间的水平应力及方向变化,由灰岩、粉砂岩到页岩,应力总体上呈减小趋势;边界断裂的影响是地应力平面上分布差异的主要成因,造成地应力降低及最大水平主应力趋于平行断层走向的偏转,地应力降低与偏转幅度主要受断裂距离控制。该结果可为宜昌地区水井沱组页岩气藏后续勘探部署及压裂施工方案设计提供依据。

鄂西地区二叠系大隆组含气页岩岩相类型及储层特征

为研究鄂西地区上二叠统大隆组含气页岩岩相类型和储层特征,本文以鄂西地区恩施市恩地2井钻井岩心为研究对象,利用X-射线衍射全岩矿物分析(XRD)、总有机碳(TOC)质量分数测定、镜质体反射率(R_(o))测定、干酪根镜检、场发射扫描电镜(FE-SEM)观察、CO_(2)和N2吸附实验、页岩含气量测定、微量元素测定等方法开展精细研究。结果显示:鄂西地区二叠系大隆组主要发育的岩相类型包括硅质岩相、黏土质硅质岩相和混合质硅质岩相,其中黏土质硅质岩相是大隆组有机碳质量分数最高的岩相类型;大隆组页岩孔隙类型多样,微孔和介孔贡献了页岩主要的孔隙体积和孔比表面积;高有机碳和高黏土矿物有利于页岩气的聚集和页岩中微小孔隙(孔径<50 nm)系统的建立,微孔和介孔中的吸附气是总含气量的重要组成部分。以含气量和有机碳质量分数为指标建立鄂西二叠系大隆组页岩评价标准,黏土质硅质岩相和混合质硅质岩相为Ⅱ_(1)类优势岩相类型,硅质岩为Ⅱ_(2)类页岩气优势岩相类型,恩地2井1 241.0~1 250.4 m井段为页岩气“甜点段”。页岩微量元素和有机碳质量分数关系表明大隆组高有机质含量是高古生产力和水体还原环境的共同结果,其中高古生产力是有机质富集的主要原因。

Chitinozoans from the Fenxiang Formation (Early Ordovician) of Yichang,Hubei Province,China

Chitinozoans collected from upper Tremadocian to lower Floian strata of Chenjiahe section, Yichang, western Hubei, China comprise six species belonging respectively to the genera Euconochitina including a new species, Euconochitina fenxiangensis, Lagenochitina and Bursachitina, together with Desmochitina sp. and Eremochitina sp. The chitinozoan succession across the interval is correlated with relevant conodont and chitinozoan biozones and two new regional chitinozoan biozones, the Lagenochitina destombesi Biozone and the Euconochitina symmetrica Biozone are proposed based on their stratigraphic ranges in the Fenxiang to Honghuayuan formations in the Chenjiahe section.

有机质激光拉曼光谱温度计应用——以鄂西灯影组为例

激光拉曼光谱测试是一种快速、简便且对样品无损的分析方法,在评估深时地质样品中碳质物热演化历史方面具有显著优势,但在其使用过程中还存在较大的争议。以鄂西地区灯影组碳酸盐岩为研究对象,通过批量激光拉曼光谱测试,计算获得平均拉曼温度为201~226℃,该温度变化在可接受的范围内。灯影组白马沱段与蛤蟆井段白云岩拉曼温度偏高且较为稳定,而石板滩段灰岩单个样品拉曼温度范围较广(180~230℃),在不同有机质富集程度下拉曼光谱特征差异大,垂向上温度波动也较为明显,I_(1350)/I_(1600)值(0.5~1.5)在石板滩段也呈现相似的分布特征,但其与有机碳同位素比值(δ^(13)C_(org))、总有机碳(TOC)含量之间不存在相关性。结果表明,有机质激光拉曼光谱(RSCM)温度计在评估深时地质样品埋藏变质温度具有较大潜力,在使用时应以同一盆地中最高变质温度为准,并增大单个样品中数据采集点数以减少误差;灯影组有机质拉曼温度不均一性是由于不同有机质富集程度的不均匀热演化程度导致的,其总体上处于极低级埋藏变质温度条件,有利于埃迪卡拉后生动物化石的保存。

鄂西咸丰地区五峰组—龙马溪组火山凝灰岩发育特征及其对页岩有机质富集的影响

鄂西咸丰地区五峰组—龙马溪组富有机质泥页岩中含多层火山凝灰岩,但前人对火山活动与海相页岩有机质富集的内在关联缺乏系统的研究。依托咸丰地区鄂咸页1井岩心及露头资料对五峰组—龙马溪组富有机质泥页岩及火山凝灰岩系统采样,开展岩矿鉴定、微量元素、稀土元素及有机碳含量(TOC)测试,阐明了五峰组—龙马溪组火山凝灰岩分布特征、源岩成分、构造背景及成因机制,探讨了该沉积时期火山活动及其对页岩有机质富集的影响。结果表明,五峰组—龙马溪组可分为火山凝灰岩密集段、次密集段和不发育段,火山凝灰岩原始岩浆性质以中性安山岩为主,火山灰来源于扬子北缘与古秦岭洋的碰撞闭合形成岛弧的火山喷发事件。火山灰是晚奥陶世—早志留世陆源碎屑补给不足的中扬子滞留海盆重要的物质来源,一方面为海洋微生物生长提供了丰富的营养元素,提高了海洋古生产力;另一方面火山作用促使海洋形成缺氧环境,利于有机质的埋藏与保存。研究成果可为鄂西地区五峰组—龙马溪组页岩气进一步勘探提供基础地质资料。

基于联合时序InSAR技术的矿区沉降隐患区识别

针对目前单一InSAR解译技术方法在复杂地表形变解译中精度及可靠性有限的难点,提出了利用PS-InSAR(persist scatterers InSAR)、SBAS-InSAR(small base-line subsets InSAR)这2种时序InSAR技术联合进行山地矿区地面沉降隐患区圈划的方法。以湖北省宜都市松宜矿区为例,基于大样本理论,利用矿区内高精度的PS点形变结果,校正具有高空间覆盖率的SBAS-InSAR处理结果,从而进一步提高地表形变监测精度并增加形变靶区范围圈划的准确度。通过对比使用单一PS-InSAR技术和经过PS-SBAS联合方法处理后得到的典型形变点时序曲线及野外实地调查,验证了解译结果的可靠性。研究表明:联合时序InSAR技术可以提高地表沉降监测精度并增加地表变形靶区范围圈划的准确度,为类似山地矿区的地面沉降隐患监测与分析提供新的技术思路。

鄂西鹤峰地区牛蹄塘组石煤中稀土元素分布规律及其赋存特征

扬子地区下寒武统牛蹄塘组石煤地层是鄂西地区重要的赋矿层位,前人多对该区域牛蹄塘组页岩气成藏开展调查研究工作,而对牛蹄塘组石煤中元素富集异常关注不够,为探讨鄂西鹤峰地区牛蹄塘组石煤富矿元素富集状态,本文对鹤地3井牛蹄塘组石煤地层展开稀土微量元素分析测试。结果表明:鹤峰地区牛蹄塘组石煤层中Li、Sc、Co、Ga、Ta、Tl、Zn、Nb、Th、Cd、In、Cs元素含量处于轻度富集状态,Cu、Ni、Mn、Cd元素含量处于富集状态,Rb、U、Ba、Cr、V、Mo元素含量处于高度富集状态。稀土元素总量(∑REE=211.10μg/g)较高,轻与重稀土元素均相对富集,轻稀土分馏程度高而重稀土元素分馏程度低,稀土元素配分模式与上地壳基本一致。本研究总结了鄂西鹤峰地区牛蹄塘组石煤伴生的稀土元素分布规律及赋存特征,为湖北省石煤及其伴生矿的成矿规律研究提供新的思路。

古代巴族与鄂西土家族文化符号比较研究

古代巴人与土家族的关系问题一直是学术界不懈探索的热点课题。本文选择鄂西土家族这一支为研究对象,以卡西尔的符号学理论为基础,通过对语言、神话、宗教以及艺术等符号多方面、多层次的比较,我们得出结论,二者在历史族源、宗教习俗以及文化艺术等方面都是一脉相承的。简而言之,鄂西土家族文化是对古代巴文化的继承与发展。本研究既为古代巴人族源研究、巴文化发展演变研究提供重要线索,又进一步厘清了巴文化与鄂西土家族文化之间的渊源关系。