Construction of well logging knowledge graph and intelligent identification method of hydrocarbon-bearing formation

Based on the well logging knowledge graph of hydrocarbon-bearing formation(HBF),a Knowledge-Powered Neural Network Formation Evaluation model(KPNFE)has been proposed.It has the following functions:(1)extracting characteristic parameters describing HBF in multiple dimensions and multiple scales;(2)showing the characteristic parameter-related entities,relationships,and attributes as vectors via graph embedding technique;(3)intelligently identifying HBF;(4)seamlessly integrating expertise into the intelligent computing to establish the assessment system and ranking algorithm for potential pay recommendation.Taking 547 wells encountered the low porosity and low permeability Chang 6 Member of Triassic in the Jiyuan Block of Ordos Basin,NW China as objects,80%of the wells were randomly selected as the training dataset and the remainder as the validation dataset.The KPNFE prediction results on the validation dataset had a coincidence rate of 94.43%with the expert interpretation results and a coincidence rate of 84.38%for all the oil testing layers,which is 13 percentage points higher in accuracy and over 100 times faster than the primary conventional interpretation.In addition,a number of potential pays likely to produce industrial oil were recommended.The KPNFE model effectively inherits,carries forward and improves the expert knowledge,nicely solving the robustness problem in HBF identification.The KPNFE,with good interpretability and high accuracy of computation results,is a powerful technical means for efficient and high-quality well logging re-evaluation of old wells in mature oilfields.

Experimental Study on Hydrocarbon Formation Due to Reactions Between Carbonates and Water or Water Bearing Minerals in Deep Earth

In order to investigate the mechanism of formation of abiogenetic hydrocarbons at the depth of the Earth, experimental research on reactions between carbonates and water or water bearing minerals was carried out at the pressure of about 1 GPa and the temperature range of 800-1500℃. The reactions took place in an open and nonequilibrium state. Chromatographic analyses of the gas products indicate that in the experiments there were generated CH 4 dominated hydrocarbons, along with some CO 2 and CO. Accordingly, we think there is no essential distinction between free state water and hydroxy in the minerals in the process of hydrocarbon formation. This study indicates that reactions between carbonates and water or water bearing minerals should be an important factor leading to the formation of abiogenetic hydrocarbons at the Earth’s depth.

Ore-Bearing Formations of the Precambrian in South China and Their Prospects

In the Precambrian System of the Yangtze and Cathaysian plates six ore-bearing formations can be identified: the Cu-Pb-Zn-bearing formations in volcanic rocks of marine facies of the Neoarchean-Paleoproterozoic, Cu-Au-bearing formations and Pb-Zn-bearing formations in volcanic rocks of marine facies of the Mesoproterozoic, Pb-Zn-bearing formations in volcaniclastic rock and carbonate rock of the Neoproterozoic, Fe-Mn-bearing formations in the volcaniclastic rock of the Neoproterozoic, and Ni-Cr-serpentine-bearing formations in ophiolite and ultrabasic rock of the Meso- and Neoproterozoic. They were mostly formed in the marginal rift valleys of the Yangtze and Cathaysian plates, where occur stratabound and stratiform ore deposits, thermal deposits and porphyry polymetallic deposits. The six regions with ore-bearing formations have good prospects for ore deposits.

Ore-bearing Formations and Mineral Resource Prospects of the Peripheral Areas of the Tarim Block

The tectonic development of the Tarim block has experienced four stages, i. e. Earth's core accretion and block formation in the Precambrian, margin splitting, opening-closing and piecing up in the Early Palaeozoic, rift formation and plate unification in the Late Palaeozoic, and basin-mountain coupling and landform shaping in the Meso-Cenozoic, forming six ore-bearing formations and ore deposits of various genetic types in the Tianshan Mountains, Kunlun Mountains and Altun Mountains. In the peripheral areas of Tarim there are four giant intercontinental metallogenic belts passing through, the Central Tianshan and southwestern Tianshan belts in the former USSR and the Qinling-Qilian-Kunlun and Palaeo-Tethys belts in China. According to the macro-analysis on the nearly one thousand known deposits (occurrences) and geophysical-geochemical anomalies, and the information from reconnaissance in some areas, the region has very good prospects for mineral resources. Some of the metallogenic belts may well become the reserve bases for exploration of mineral resources in China.

Influence of Lithological Characters of Coal Bearing Formation on Stability of Roof of Coal Seams

Lithology is one of the important factors influencing the stability of roof of coal seams. In order to investigate this, the phenomenon of underground pressure and distribution of pressure were studied by using the local observation and simulation test with similar materials. The observation results show that the distance of initial weighting and periodic weighting of the mudstone roof is shorter than that of sandstone roofs. The sandstone roof with a high strength has a longer distance of initial weighting and periodic weighting, the abutment stress on the working face is big and the height of caving and fracture zone is high. The peak point of abutment stress in the sandstone roof is near to the working face and the pressure bump is inclined to occur. The result is contrary to that in case of the mudstone roof with a low strength. While in the transition zone of nipped sandstone, roof rock-mass is broken and is poor in stability, therefore, it is difficult to hold the roof.

Experimental Study on the Mechanism for the Formation of Sn- bearing Granite in Northern Guangxi

Experimental results have proved that the Xuefengian Sn-bearing biotite granites were formed by remelting and recrystallization of the Proterozoic metamorphic rocks of the Sibao Group at 500× 105-2000× 105 Pa and 750-570℃ and further testified that the F- and B-bear-ing aqueous solution played an important part in decreasing the formation temperature of the rocks. The results tally with the reality of the field geology. The authors have thus brought to light the mechanism for the formation of the Sn-bearing biotite granites and expounded the significance of their formation in the crust dynamics of South China.

Formation Depth of Coesite-Bearing Eclogite,Dabie UHPM Zone,China

The plastic deformation of garnet in coesite bearing eclogite, quartz eclogite and garnet amphibolite of the UHPM complex in Yingshan County in the Dabie Mountains has been studied. The stress generated by the strong tectonic movement was an important component of the total pressure that resulted in the formation of the eclogite in the Dabie UHPM zone. The three dimensional tectonic principal stresses and additional tectonic stress induced hydrostatic pressure [ p s=( σ 1+ σ 2+ σ 3)/3] are reconstructed according to the differential stress and the strain ratio ( α ) of the garnet in the minor coesite bearing eclogite of the Yingshan County. Then the gravity induced hydrostatic pressure ( p g) is calculated following the equation p minus p s, where p is estimated to be 2.8 GPa based on the quartz coesite geobarmeter. Therefore, the thickness of the rock column overlying the coesite bearing eclogite in the Ying shan County is determined ≥32 km. This estimation, significantly different from ≥100 km, the previous one obtained solely based on the weight/specific weight ratio (W/SW), offers a proper explanation for the puzzle that no tracer of the addition of mantle derived material has been found in the Dabie UHPM zone during the process of UHPM, although a number of researchers claim that this process took place at the depth of the mantle (≥100 km). It is concluded that attention should be paid to the additional tectonic stress induced hydrostatic pressure in the study of UHPM zones.

Gold-bearing formations and their evolution in central Inner Mongolia

In central Inner Mongolia, five gold bearing formations (Xiajining, Dongwufenzi, Wulashan, Baiyunebo and Bainaimiao Groups) belong either to volcano sedimentation or clasolite sedimentation. They formed in different tectonic environments such as an Archean rift zone (Xiajining and Dongwufenzi Groups), an Early Proterozoic stable basin (Wulashan Group), a Middle to Late Proterozoic continental rift zone (Baiyunebo Group), and a Paleozoic island arc environment (Bainaimiao Group). Gold contents in the gold bearing formations in the area are higher than those of other gold bearing formations in the North China Craton. However, as most gold bearing formations in the area are limited, there are a few big gold deposits in central Inner Mongolia. Gold contents in all formations were strongly influenced by migmatization and ductile shearing, the former process prompting mobilization, and the latter process resulting in gold enrichment in ductile shear zones. During the development of Archean to Proterozoic gold bearing formations, gold migrated from the mantle to the crust, then through the crust, finally deposited at the earth’s surface.

A simulation study of formation permeability as a function of methane hydrate concentration

We modeled and studied the permeability of methane hydrate bearing formations as a function of methane hydrate concentration by artificially varying the T2 distribution as well as using a tube-sphere model.We varied the proportion of irreducible and movable water as well as the total porosity associated with the T2 distribution and found the normalized permeability as a function of methane hydrate concentration is dependent of these variations.Using a tube-sphere model,we increased the methane hydrate concentration by randomly placing methane hydrate crystals in the pore spaces and computed the permeability using either the Schlumberger T2 relaxation time formula or a direct calculation based on Darcy＇s law assuming Poiseuille flow.Earlier experimental measurements reported in the literature show there is a methane hydrate concentration range where the permeability remains relatively constant.We found that when the Schlumberger T2 relaxation time formula is used the simulation results show a curve of normalized permeability versus methane hydrate concentration quite close to that predicted by the Masuda model with N = 15.When the permeability was directly calculated based on Darcy＇s law,the simulation results show a much higher normalized permeability and only show a trend consistent with the experimental results,i.e.,with a permeability plateau,when the methane hydrate crystals are preferentially placed in the tubes,and the higher the preferential probability,the larger the range where the permeability has a plateau.

Distribution and gas-bearing properties of Permian igneous rocks in Sichuan Basin, SW China

Based on the analysis of outcrop, seismic, logging and drilling data, combined with exploration practice, the characteristics,distribution, reservoir performance and gas-bearing properties of Permian igneous rocks in Sichuan Basin are studied. The study shows that central volcanic eruptive facies are developed in Sichuan Basin, and their lithological assemblages and distribution characteristics show obvious differences. The igneous rocks are mainly distributed in three regions: the southwestern part of the basin has dominantly largescale overflow facies basalts; the central and western part of the basin, Jianyang-Santai area, develop intrusive rocks, volcanic lavas(basalts)and pyroclastic rocks; and the eastern part of Sichuan, Dazhou-Liangping area, only develop diabase and basalts. Five aspects of understandings are achieved:(1) The Upper Permian igneous rocks can be divided into intrusive rocks and extrusive rocks, with the extrusive rocks as the main body. The chemical compositions of the extrusive rocks are characterized by both alkaline basalt and tholeiitic basalt, and belong to the subalkaline type of transitional basalt magma eruption.(2) There are obvious rhythmic structures vertically among overflow facies basalt, and the single rhythmic layer consists of, from bottom up, pyroclastic rocks(undeveloped), gray and dark gray porphyritic basalts(unstable), dark gray and purple microcrystalline-cryptocrystalline basalts, dark greyish green porous and amygdaloid basalts; the central volcanic eruption shows the rhythm and the vertical sequence of volcanic clastic rocks(agglomerates and breccias), volcanic lava, tuffaceous lava from bottom to top.(3) The pore types of basalt and pyroclastic rocks are diverse, mainly dissolution pore and de-vitrification micropore, but their physical properties are different. Basalt is characterized by ultra-low pore permeability, small reservoir thickness, and reservoirs are distributed in the upper and middle parts of the cycle, with poor lateral comparability. Volcanic clastic rocks are medium to high porous reservoirs(Well YT1: porosity: 8.66%?16.48%, average 13.76%) with large thickness and good reservoir quality.(4) Natural gas in basalts in southwestern basin mainly comes from Middle Permian, and natural gas in volcanic clastic rocks in central and western basin comes from Cambrian Qiongzhusi Formation.(5) Analysis of igneous reservoir-forming conditions in different areas shows that there are relatively insufficient gas sources and great differences in preservation conditions in southwestern basin.Reservoirs are poorly developed and gas-bearing is complex. The Jianyang-Santai area in the central and western part of Sichuan Basin has abundant hydrocarbon sources, developed reservoir, favorable preservation conditions and favorable gas geological conditions, and it is a favorable area for gas exploration.

Distributed bearing-based formation control of unmanned aerial vehicle swarm via global orientation estimation

Most existing formation control approaches for Unmanned Aerial Vehicle(UAV)swarm assume that global position and global coordinate frame are directly available for each agent.To extend the application domain,this paper proposes a distributed bearing-based formation control scheme,without any reliance on global position or global coordinate frame.The interactions among UAVs are described by a directed topology with two-leader structure.To address the issue of unavailable global coordinate frame,we first present a distributed orientation estimation law for each UAV to determine its orientation under the coordinate frame of the first leader.Based on the orientation estimation,we then design a bearing-based formation control law to globally asymptotically track target moving formations.Finally,simulation results are provided to validate the proposed method,which show that the translation,scale and orientation of the formation can be flexibly controlled via two leaders.

FUSULINID-BEARING FORMATIONS AND FUSULINID FAUNA FROM DADUN COALFIELD OF PEIXIAN,NORTHERN JIANGSU PROVINCE

In the Dadun coalfield of the Peixian distrier, Jiangsu Province, the coal-bearing strata are covered by the Quaternary deposits.In this coalfield there are 19 layers of fusulinid-bearing limestones, of which 16 layers belong to the Taiyuan formation, 3 layers to the Penchi. The lithologic characters and the

Ore-controlled Mechanism and Geochemical Characteristics of Gold-bearing Formation in Northwest Jiangxi Terrain

Based on the geological and geochemical studies on the Middle Proterozoic Jiuling Group in the Northwest Jiangxi Terrain, it is ascertained that this group is a kind of Au-bearing formation with Au-Ag-As association, and the volcanism is the key to its foundation. The Jiuling Group can be divided into two geochemical groups: high-Au layers and low-Au layers, which is due to the inhomogeneous metamorphic reformation. The discriminant functions F_1& F_2 can be established by means of Au, Ag, As, Ti, Cr, V, etc. eleven elements, and the diagram of F_1-F_2 is the distinguishing sign of the Au-bearing formation. Based on the systematic studies on two types of gold mineralization, namely, solo gold with metamorphic fluid and Au, Ag, etc. polymetallic association with magmatic fluid, the authors establish the metallogenic model of gold deposits in the area.

Calculation of Austenite Formation Kinetics of Copper-Bearing Steel During Continuous Heating

The kinetics of austenite formation in a new type of copper-bearing steel with initial microstructure composed of ferrite and bainite was investigated by using dilatometric analysis and measurement during continuous heating. The formation of austenite was observed to occur in two stages. The first stage is the dissolution of ferrite and most bainite, followed by the second stage of dissolution of bainite and formation of austenite. The first stage takes place through diffusion and the second stage through shear. The critical temperature of austenite formation during continuous heating increases with increasing heating rates, which therefore exerts a greater influence on the Ast temperature of the austenite formation. Kinetics calculation shows that the process is mainly controlled by diffusion when the heating rate is over 1℃/s.

The formation depth of coesite-bearing eclogite,Dabie UHPM zone,China,modified by tectono-original additional hydrostatic pressure

The knowledge that hydrostatic pressure is equal to the gravity value of the overlying rocks in studying a dynamic state of certain underground site is argued. It is suggested that the stress field T in the crust is a combination or superposition of total hydrostatic pressure P with differential stress σ,and the total hydrostatic pressure P at any point in the crust comprises two parts: one is spherical stress tensor PG caused by the gravity, and the other is spherical stress tensor Ps caused by tectonic stress; therefore P could not be attributed to the gravity of overlying rocks only. The results obtained by a finite-element simulation indicate that the tectono-original additional hydrostatic pressures Ps decrease gradually from the compressive zone （pcS） to the shear zone (PSHs)and to the tensile zone （PTs）, i.e.Pcs】PsHs】PTs in the same depth. On the basis of the above-mentioned research, the method of measurement and calculation of metallogenetic depth corrected by Ps is

Geological setting of some classical selenium-bearing formations in China

SELENIUM is a highly dispersed element with a lower Clarke of 0.05×10-6 and rarely forms its own independent deposits in the crust. In recent years by the discovery of a series of selenium-bearing deposits（such as Laerma selenium-gold deposit and Yutangba selenium deposit） and selenium-rich strata （westHubei, Laerma, Ziyang, Langao, northwest Hunan, etc.）, the character and genesis of the seleniumbearing formation （SBF） have been noted by many researchers. 1 Some classical SBF in China In China the classical SBFs include: （i） The Lower Cambrian SBF in Laerma, west Qinling: Thebackground value of selenium is 5.47×10-6, and the selenium content of the sillcalite and slate （mainrock type） averages 8.70×10-6 and 3.05×10-6 respectively. （ii） The Lower Cambrian SBF inZiyang and Langao, east Qinling: Selenium is present in relatively high abundance in the SBF, averaging3.89×10-6 in the slate, 2.86×10-6 in the sillcalite. （iii） The Lower Cambrian SBF in northwest Hu-

Kerogen——as a sort of organic bearer of gold in gold-bearing formations

Organic component, organic carbon and gold content analyses were used to study the relationship between gold mineralization and organic matter in major host rocks of three different chronological gold-bearing formations of South China. The results show that the organic matter of host rocks in various chronological major gold-bearing formations of South China has associated with gold mineralization in genesis. There is a positive correlation between gold and organic carbon in the host rocks of gold-bearing formations. Gold element was mainly enriched in insoluble organic matter——kerogen. Gold content of the kerogen is commonly higher from a few tens to several hundred times than that of the whole rocks, up to 5%—40% gold of the whole rocks. Gold remaining in the kerogen was considered an organic group of the kerogen to combine with ionic gold in solution through surface absorption, ion exchange complex reaction and chelation so that the kerogen could have become an important sort of organic bearer

南襄盆地泌阳凹陷古近系核桃园组页岩含油性及烃类赋存特征

南襄盆地泌阳凹陷古近系核桃园组发育优质湖相页岩层系,页岩油资源潜力巨大。前人针对该层系页岩含油性及烃类赋存状态的研究相对薄弱,可能是制约泌阳凹陷页岩油勘探突破的重要因素之一。以泌阳凹陷南部Y1井核三段Ⅲ亚段页岩为研究对象,通过岩石热解、多温阶热解、X射线衍射等地球化学分析技术,系统开展了页岩含油性、烃类赋存特征及影响因素研究。研究结果显示:核三段Ⅲ亚段页岩岩相组合主要包括长英质页岩相、云灰质页岩相和混合质页岩相,纹层结构发育。烃源岩类型整体处于好—优质范围,热演化程度处于生油阶段。有机显微组分以腐泥型为主,有机质类型为Ⅰ—Ⅱ1型。页岩含油性随埋深增大呈递增趋势,烃类赋存特征由中上部以吸附烃为主,过渡至下部以游离烃为主。碎屑矿物及有机碳含量是控制游离烃和吸附烃含量的主要因素。总体认为,核桃园组下部页岩含油饱和度指数整体高于100 mg/g,游离烃含量平均高于3 mg/g,具备较好的页岩油勘探开发前景。

凸棱非平面聚晶金刚石齿的破岩机理及在含砾地层中的应用

为提高聚晶金刚石复合片(PDC)钻头在含砾、软硬交错等不均质地层中的抗冲击性能,开展了凸棱非平面PDC齿的研究。通过仿真和室内实验对比分析了凸棱非平面齿与常规平面齿的破岩机理。与平面齿相比,凸棱非平面齿与岩石的接触应力分布更均匀,切削破岩过程中的载荷波动幅度明显更小,切削稳定性更高。凸棱齿特殊的非平面结构改变了切削齿与岩石的互作用方式,在不均质地层得到成功应用。