CONCEPT, DISTRIBUTION LAW AND FORMATION MACHANISM OF INLAND SALINE ALKALINE WETLAND─ ─ Taking Songliao Plain for Example

The paper, taking Songliao Plain for example, studied the concept, distribution law and formation mechanism of inland saline alkaline wetland. The inland saline alkaline wetland is distributed over the inland region of arid or semi arid climate; it is the wet or slightly stagnant environment, forming saline alkaline soil and salt vegetation and making the geogra phical environment fonming complex with an ecosystem of saline alkaline wetland. The laws of zone nature and non zone nature control the distribution of the inland saline alkaline wetland that extensively spreads in north part of China and other countries. The inland saline alkaline wetland is formed jointly by atmosphere, hydrosphere, lithosphere and biosphere including intellectual sphere. Under the special condition, the artificial activity is possibly the key function. In order to improve the human environment, it is a great duty confronting the whole world to rationally transform the inland saline alkaline wetland. Therefore, we presented an anti inland theory to promote the environment transformation.

Formation law and criterion of nebulous macroscopic segregation in ZL205A alloy castings

The appearance of macroscopic segregation in ZL205A alloy castings bears a super resemblance to theappearance of shrinkage porosity, and the chemical composition of the segregation is Al2Cu whose microstructure isin the form of dentrite or skeleton crystal. According to the characteristic of nebulous segregation, the formationprocess could be divided into two steps by the eutectic temperature of Al2Cu. Then a criterion for each of the twosteps is brought forward on the basis of the shrinkage porosity criterion of low pressure casting.

BACKLUND TRANSFORMATION, NONLINEAR SUPERPOSITION FORMULAE AND INFINITE CONSERVED LAWS OF BENJAMIN EQUATION

Backlund transformation, exact solitary wave solutions, nonlinear supperposi tion formulae and infinite conserved laws are presented by using TU-pattern. The algorithm involves wide applications for nonlinear evolution equations.

Formation Laws of Inorganic Gas Pools in the Northern Jiangsu Basin

In the Northern Jiangsu basin there are high pure CO2 gas pools, low condensed oil-containing CO2 gas pools, high condensed oil-containing CO2 gas pools and He-containing natural gas pools, with the δ13Cco2 (PDB) values ranging from ?2.87%o to ?6.50%o, 3He/4He 3.71 × 10?6 to 6.42 × 10?6, R/Ra 2.64 to 4.5, 40Ar/36Ar 705 to 734, belonging to typical mantle source inorganic gas pools which are related to young magmatic activity. The gas layers occur in two major reservoir-caprock systems, the terrestrial Meso-Cenozoic clastic rock system and the marine Meso-Palaeozoic carbonate rock-clastic rock system. Controlled by the difference in the scale of traps in the two reservoir-caprock systems, large and medium-scale inorganic gas pools are formed in the marine Meso-Palaeozoic Group and only small ones are formed in the terrestrial Meso-Cenozoic strata. Inorganic gas pools in this basin are distributed along the two deep lithospheric faults on the west and south boundaries of the basin. Gas pools are developed at the intersected part of the ENE-trending faults that control the half graben and the E-W tenso-shear faults, mainly distributed near the Es1, Ny1 and Ny2-Q basalt eruption centres.

Multiple UAVs cooperative formation forming control based on back-stepping-like approach

To ensure multiple unmanned aerial vehicles （UAVs）reach stable formation quickly, a cooperative guidance law basedon the back-stepping-like approach is designed in this paper.Adopting the guidance mechanism of virtue leader vehicle, thedynamic equation of tracking errors for each UAV is built. Thecommunication interactive relationships are described based ongraph theory, and the guidance law for formation reaching is ob-tained by the back-stepping-like approach. The formation stabilityis analyzed by constructing an appropriate Lyapunov function. Thesimulation results have shown that this guidance and control lawcan make each UAV converge to the trajectory of the virtue leaderultimately, and has the quicker rate of convergence and lowertracking error.

Formation patterns of Chang 9 oil reservoir in Triassic Yanchang Formation, Ordos Basin, NW China

Based on analysis of main controlling factors of Chang 9, the source rock, driving force of migration, migration and accumulation modes, reservoir forming stages and model and enrichment law of Chang 9 reservoir were examined. The study showed that the oil of Chang 9 reservoir in the Jiyuan and Longdong(Eastern Gansu) areas came primarily from the source rock of Chang 7 Member, but the oil of Chang 9 reservoir in the Zhidan area came primarily from the source rock of Chang 9 Member. There developed lithologic-structural oil reservoirs in Gufengzhuang-Mahuangshan area in northwest Jiyuan, structural-lithologic oil reservoirs in east Jiyuan, and lithologic reservoirs in Huachi–Qingcheng area and Zhidan area. The overpressure of Chang 7 Member was the driving force of oil migration. The burial history showed that Chang 9 Member experienced two stages of reservoir forming, the reservoir formed in the Late Jurassic was smaller in charging scope and scale, and the Early Cretaceous was the period when the source rock generated oil and gas massively and the Chang 9 reservoir came into being. Along with the tectonic movements, Chang 7 bottom structure turned from high in the west and lower in the East in the sedimentary stage to high in the east and lower in the west in the hydrocarbon accumulation stage and at last to gentle western-leaning monoclinal structure at present. In Early Cretaceous, the Chang 7 bottom structure was the lowest in the west of Huanxian-Huachi-Wuqi-Dingbian areas, so the oil migrated laterally towards the higher positions around after entering the reservoir. In the main reservoir forming period, Chang 7 bottom had an ancient anticline in Mahuangshan-Hongjingzi area of west Jiyuan, controlling the oil reservoir distribution in west Jiyuan.

Development of Karst Formation in Area 4 of Tahe Oilfield

The main oil-bearing formation of Area 4 of Tahe oilfield is in Yingshan Group of Ordovician consisted of thick pure limestone. The types of the pore space contain the pore, fissure, cave as well as fracture formed by solution collapse. The primary porosity and tectonic fracture are of poor growth. Therefore, the formation growth is mainly controlled by hydraulic units of the palaeo-karst. There are three palaeo-hydraulic zones: vadose zone (including infiltration sub-zone and percolation sub-zone), phreatic zone and tranquil zone. They are identified by retrieving the palaeo-geographical karst environment. The pore space of the infiltration zone is mainly solution fissures, small solution cavities and solution pores. The growth and lateral connection of the formation are favorable. The reservoir/formation ratio is 0. 54. The pore space of the phreatic zone developed large size cavities and fractures related to cave collapse. The height of the cavity can reach 71m. The fractures by collapse have a influencing range of more than 100m, and its reservoir/formation ratio is 0. 51. But the lateral connection is unfavorable. The percolation subzone and the tranquil zone are of relatively poor growth with the reservoir/ formation ratio less than 0. 3.

Shale oil enrichment evaluation and production law in Gulong Sag,Songliao Basin,NE China

Based on the results of drilling,tests and simulation experiments,the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evolution,shale oil occurrence,and pore/fracture evolution mechanism.In conjunction with a substantial amount of oil testing and production data,the Gulong shale oil enrichment layers are evaluated and the production behaviors and decline law are analyzed.The results are drawn in four aspects.First,the Gulong shales are in the stage of extensive hydrocarbon expulsion when R_(0) is 1.0%-1.2%,with the peak hydrocarbon expulsion efficiency of 49.5%approximately.In the low-medium maturity stage,shale oil migrates from kerogen to rocks and organic pores/fractures.In the medium-high maturity stage,shale oil transforms from adsorbed state to free state.Second,the clay mineral intergranular pores/fractures,dissolution pores,and organic pores make up the majority of the pore structure.During the transformation,clay minerals undergo significant intergranular pore/fracture development between the minerals such as illite and illite/smectite mixed layer.A network of pores/fractures is formed by organic matter cracking.Third,free hydrocarbon content,effective porosity,total porosity,and brittle mineral content are the core indicators for the evaluation of shale oil enrichment layers.Class-I layers are defined as free hydrocarbon content equal or greater than 6.0 mg/g,effective porosity equal or greater than 3.5%,total porosity equal or greater than 8.0%,and brittle mineral content equal or greater than 50%.It is believed that the favourable oil layers are Q2-Q3 and Q8-Q9.Fourth,the horizontal wells in the core area of the light oil zone exhibit a high cumulative production in the first year,and present a hyperbolic production decline pattern,with the decline index of 0.85-0.95,the first-year decline rate of 14.5%-26.5%,and the single-well estimated ultimate recovery(EUR)greater than 2.0×10^(4)t.In practical exploration and production,more efforts will be devoted to the clarification of hydrocarbon generation and expulsion mechanisms,accurate testing of porosity and hydrocarbon content/phase of shale under formation conditions,precise delineation of the boundary of enrichment area,relationship between mechanical properties and stimulated reservoir volume,and enhanced oil recovery,in order to improve the EUR and achieve a large-scale,efficient development of shale oil.

断陷湖盆细粒区页岩组构特征与页岩油富集成藏规律:以黄骅坳陷古近系为例

为明确断陷湖盆细粒区页岩微观组构特征及页岩油富集成藏规律,基于黄骅坳陷古近系孔二段、沙三段、沙一段3套页岩层系取心、测井、录井及试油等资料,综合利用矿物分析-场发射扫描电镜、氩离子抛光-场发射扫描电镜、聚焦离子束-场发射扫描电镜等技术手段,针对页岩样品开展多尺度、多维度精细表征,从微观、定量的角度系统分析了页岩矿物、有机质、孔隙及页岩油赋存特征,揭示了页岩油成藏富集规律并建立了富集模式。研究结果表明:在微观视域下,多类型矿物以“组分混合”和“组构叠置”构成复杂页岩类型;储集空间可划分为无机孔隙、有机孔隙和微裂缝3大类9小类,其中无机孔隙贡献率平均可达85%以上,孔径<50 nm的孔隙占据储集空间的主体;微观上有机质可划分为同沉积有机质、交生分异有机质和运移充填有机质3种类型;烃类主要赋存于长英质纹层、灰云质纹层或粉砂岩纹层中。基于矿物、有机质、储集空间、烃类4个要素的“四元耦合”页岩油富集成藏规律,建立了3类富集成藏模式。在该模式指导下,沧东凹陷孔二段实施多口水平井获高产,优质页岩油区块已经实现当今油价下的效益开发,歧口凹陷沙三段及沙一下亚段页岩油均获得重要突破,展示出黄骅坳陷古近系页岩油具有广阔的资源前景。

致密砂岩气藏高产富集规律研究——以川西坳陷新场—合兴场须家河组二段气藏为例

四川盆地川西坳陷须家河组致密砂岩气藏储量巨大,具有砂体厚、物性差、非均质性强、气水分布复杂等特点,给气藏的开发评价及建产选区带来极大难度。为实现气藏高效评价开发,以新场—合兴场须家河组二段气藏为研究对象,基于气藏静、动态特征,深度分析了典型井的古、今构造位置,断层特征,裂缝和储层品质等对产能的影响,明确气井高产的主要控制因素。通过分析各控制因素的综合作用,结合成藏研究成果,探讨天然气富集高产规律,结果表明新场—合兴场须家河组二段气藏气井可分为高产高效、中产中效、低产低效3种类型。高产高效和中产中效气井产量高、稳产好,主要分布在北南向四级烃源断层和五级断层附近,裂缝发育、优质储层厚度大,具有良好的地质条件。明确了气藏富集高产遵循古、今构造控藏,烃源断层控富,有效裂缝控产,优质储层控稳的规律,为该气藏的高效开发奠定了基础。

松辽盆地北部全油气系统成藏模式与勘探潜力

松辽盆地作为一个多套优质烃源岩大面积发育的大型陆相叠合盆地,由于受多期构造与沉积的复合控制和改造,油气藏富集规律复杂多样。为进一步落实松辽盆地北部油气成藏条件与勘探潜力,基于全油气系统新概念,将松辽盆地北部划分为2个全油气系统:以青山口组为生油岩,嫩江组为区域盖层的储盖组合,形成了常规油、致密油、页岩油多类型有序成藏的上部石油系统;以沙河子组为烃源岩,登娄库组为区域盖层的储盖组合,形成了营城组火山岩、沙河子组砂砾岩等多种气藏差异富集的下部天然气系统。以此为基础,研究了松辽盆地北部油气藏的基本油气地质条件、常规-非常规油气的共生特征与油气分布情况。上部石油系统青山口组源岩经过生烃增压、幕式排烃后,地层压力释放,页岩储层形成自封闭体系,内部干酪根持续生烃、油气原位成藏,形成大规模连续分布的“立体式”页岩油藏;扶余油层致密油受生烃增压作用的控制、油气向下“倒灌”,形成断裂下排-横向运移、源-储侧向对接充注成藏。下部天然气系统沙河子组源岩持续生烃,受源储关系、储层特征和输导通道等成藏要素的耦合控制,形成中央古隆起“源储叠置、不整合输导、淋滤层聚气、高部位富集”,营城组火山岩气藏“下生上储、深断裂通源、高部位聚气”和沙河子组致密气“自生自储、断裂控砂、超压控富”等3种成藏模式。研究成果对松辽盆地不同类型油气资源分布预测和勘探具有重要指导意义。

煤与油气协调开采物理相似模拟研究

针对煤与油气协调开采中,煤层开发扰动油气圈闭层稳定性及油气井筒的问题,利用二维模拟试验开展了煤与油气开采地层响应规律研究;采用“先油气后煤炭”的开采工序,得到了煤与油气各覆岩层的应力演化、破断变形特征及油气井筒变形破坏规律。研究结果表明:若油气层高强度抽采至采收完毕,模型整体结构未出现明显扰动,仅层间岩层局部存在应力集中现象,而此时对煤层进行开采会对下方200 m处油气层产生一定扰动;采动初期,油气层采收边界上方应力不断上升,煤层底板存在应力传递现象,煤层顶板无明显应力变化,初次扰动范围为100 m,二次扰动范围为75 m;当进入充分采动阶段,油气层采收边界上方应力集中沿水平向右侧偏移,煤层底板相继经历应力集中-卸压的过程,层间岩层结构趋于稳定,岩层运移程度逐渐向煤层顶部附近岩层转移,说明煤层采动作用在叠置资源协调开采过程中对整体岩层稳定性影响程度较大,应着重关注煤层开采对煤与油气协调开采中的影响;覆岩内井筒主要破坏模式为剪切变形破坏,位于工作面中心处的井筒下侧则发生拉伸-剪切变形破坏,应着重关注工作面中心处的井筒防护。

双无人机对地快速移动目标跟踪的构型设计与控制方法

为实现对地面快速移动目标的探测跟踪,基于无人机侦察载荷的误差模型,设计了双无人机编队跟踪目标的构型与跟踪控制律。面向持续跟踪的典型应用场景,设计了基于Leader-Follower的双机编队构型,并基于相机误差模型建立了双无人机探测叠加区域的误差分布模型,以此确定了目标与无人机编队的位置关系。之后,基于无人机与目标的视觉关系定义长机的矢量前置角和与目标之间的距离为跟踪误差,设计了基于李雅普诺夫方法的跟踪控制律,并证明跟踪控制的渐近稳定性。设计了僚机相对于长机的编队控制律,以保持双机平行编队的构型。仿真结果表明,目标机动运动时,双无人机系统能够在较短时间内收敛,实现对目标的持续稳定跟踪。

The basic law of the formation and expansion in urban agglomerations

Urban agglomerations are formed when a country is in the advanced stages of industrialization and urbanization. They are highly integrated groups of cities that form and develop through a natural, gradual process as the relationship between them changes from one of competition to assimilation following law of natural development. China is currently in a new stage of transitional development characterized by its New-Type Urbanization Plan. It has entered a new era in which it is a global leader in urban agglomeration development, and China’s research and development models are being imitated and adopted by countries around the world. This paper adopts a theoretical approach to propose the basic law governing the formation, development and expansion of urban agglomerations. This includes the stage-based formation and development law, multi-scale intensive-use transmission law,crystal-structure spatial composition law, egg-shaped expansion evolution law,'saplings-to-forest' natural growth law, and sustainable development incremental increase law.Guided by these law, China has created a hierarchical organizational configuration for optimizing the spatial structure of its urban agglomerations. It has also formulated urban agglomeration development plans and proposed research-based measures to resolve problems specific to urban agglomerations and to promote their sustainable development. The law governing the formation, development and expansion of urban agglomerations play an important role in guiding their development in China and will play a greater role in the future.

鄂尔多斯盆地双河地区延长组长6油层组地层水化学特征分布规律

致密油藏油水关系复杂,地层水化学组分及其分布规律对指导致密油勘探具有重要意义。基于此,对双河地区长6油层组地层水化学组成、矿化度、水化学特征参数与沉积微相、有效厚度及产能之间的关系进行了深入研究。研究表明,双河地区地层水类型主要为CaCl_(2)型,地层水的矿化度主要分布在2201.2~153670.9 mg/L,平均为53947.2 mg/L。矿化度在50000 mg/L之前,含油饱和度随着矿化度的增加而降低的,而在50000 mg/L之后,含油饱和度随着地层水矿化度的增加而增加。这是由于,较高的矿化度代表好的保存条件,利于油气长期大规模聚集,因而含油饱和度较高;而当目的层矿化度处于10000~20000 mg/L相对低的范围时,主要对应3~5 m薄层单砂体组成的复合砂体,因而含油饱和度也相对较高。分析认为,目的层矿化度、钠氯系数、镁钙系数特征均表明目的层处于相对封闭的沉积环境,有利于油气的保存,这些水化学参数均与致密油藏聚集及产能有较为显著的相关性。

准噶尔盆地中拐地区致密砂岩气成藏特征及富集规律

致密砂岩气作为一种清洁高效的低碳能源,对能源消费结构转型升级和实现“双碳”目标具有重要意义。准噶尔盆地西北缘中拐地区二叠系佳木河组致密砂岩气的成藏特征及富集规律认识不清。基于钻井、测井、三维地震、岩心和实验分析测试资料,综合分析研究区致密砂岩气成藏地质特征、富集规律及高产主控因素。研究结果表明:中拐地区二叠系佳木河组致密砂岩气类型主要由油型气、煤型气及混合气组成,气源主要来自沙湾凹陷风城组及下乌尔禾组烃源岩,佳木河组烃源岩可能供烃,具有多源供烃特征;气藏类型为岩性-地层圈闭型,具有远源运移,多期次聚集成藏特征;致密储层受浊沸石矿物等溶蚀作用在局部地区形成物性相对较好的储层“甜点”,其主要分布在研究区东部,纵向上主要发育在4320~4640 m和4830~4900 m深度段,高产层段主要集中在上部“甜点”带。致密砂岩气藏的富集及高产受控于有利成岩相带上的储层“甜点”和局部发育的古凸起及构造裂缝。

西部高山峡谷区重大滑坡成生规律及灾变演化机理研究进展

中国西部水电工程大多位于高山峡谷内,复杂的工程地质条件导致峡谷库岸滑坡灾害分布广泛。基于西部高山峡谷水电工程区的工程地质特征,系统分析了地形、地质构造、滑体物质、坡体结构和水文地质条件与滑坡的成生发育关系,并总结了典型滑坡的类型、特征及其灾变演化的力学机制。研究结果表明:西部高山峡谷滑坡以坡度30°~50°、高程超过1000 m、体积超过100×10^(4)m^(3)的滑坡为主;三叠系、奥陶系和志留系为典型的易滑地层;降雨和水库蓄水导致侵蚀基准面抬升、侵蚀范围扩大,库区水位的反复升降导致涉水滑坡体前缘岩土体性质降低。西部高山峡谷区滑坡类型主要分为以牵引式滑坡、推移式滑坡和复合式滑坡为主的堆积层滑坡以及以顺层岩质滑坡、溃屈型岩质滑坡、反倾岩质滑坡和座落式滑坡为主的岩质滑坡,不同类型的滑坡其演化过程不同,滑坡灾变机理也有所差异。研究成果将对西部高山峡谷区的滑坡识别、监测、预警以及防治具有一定的指导意义。

2019年湖南攸县7·15大型岩溶地面塌陷的发育分布规律及形成机理

2019年7月15日,湖南株洲市攸县樟井村发生大规模岩溶地面塌陷,严重威胁当地人民群众的生命和财产安全。为查明7·15大型岩溶地面塌陷的形成机理,通过地球物理勘探、水文地质工程地质钻探、地下水监测、水化学分析等多种手段对岩溶地面塌陷区开展了详细的调查研究,分析了该岩溶地面塌陷的发育规律及致灾因素。结果表明:7·15大型岩溶地面塌陷是由降雨主导,在地表覆盖层软化减强、岩溶气爆和渗流潜蚀效应等多种不良因素共同作用诱发的自然塌陷;地面塌陷位于断层、褶皱等构造密集发育的可溶性碳酸盐岩区域,区内岩溶强烈,广泛发育的溶洞、落水洞、泉、地下暗河等岩溶形迹为地面塌陷的形成提供了条件;7·15大型岩溶地面塌陷的形成演化可分为降雨诱发的地表覆盖层土体软化减强和封盖增荷、降雨导致地下水水位上升引发的岩溶气爆、地下水渗流潜蚀加速顶板垮塌形成土洞、土洞扩大及顶板失稳4个阶段。该研究结果可为类似地质条件地区的岩溶地面塌陷预测预报与防治提供科学依据。

基于动态事件触发的无人艇编队控制方法

针对多无人艇编队系统出现通信拓扑发生改变的问题,提出一种基于动态事件触发的无人艇编队控制方法。首先,在考虑编队误差和控制输入的基础上,提出一种基于成本的切换律以确定切换时刻;其次,设计一种具有可调阈值的动态事件触发机制以减少通信负担;然后,为解决外界干扰以及未知动力学,构造扰动观测器来估计扰动从而设计分布式控制器,能够减轻外界干扰的影响,实现无人艇编队控制。通过李雅普诺夫函数具体分析2种情况下的稳定性,可得该系统能够实现一致性。最后,通过仿真证明了所提出方案的有效性。

渤海海域浅层原油物性分布规律与主控因素

明化镇组下段和馆陶组(本研究称浅层)是渤海海域主力含油层系,其原油物性平面变化较快,但区域上原油物性平面分布规律缺乏系统研究,制约了浅层油气分布规律认识。本次研究结合区域地质认识,利用丰富的钻井、原油分析大数据资料,从浅层原油物性特征分析出发,探讨其分布规律的主控因素。研究认为:①渤海海域浅层原油物性参数在凸起区、凹陷区差异明显,凹陷区原油普遍具有“四低一高”的特征,即密度低、黏度低、胶质+沥青质低、含硫量低、含蜡量高,而凸起区原油表现为相反的“四高一低”;②油藏埋深、保存条件、运移距离控制了浅层原油物性的差异分布,埋深大、保存好且运移距离短时,原油降解作用和色层效应弱,利于形成原油物性较好的油藏;③烃源岩条件主要影响渤海东部盆缘凹陷的浅层原油物性,烃源岩热演化程度较高、水体环境偏淡时,利于形成原油密度小、黏度小、含硫量低的优质油藏。研究成果总结了渤海海域明下段和馆陶组原油物性平面分布规律及控制因素,为寻找浅层优质油藏潜力区带具有指导意义。