2004 Vol. 26, No. 1

Display Method:
FORMING MECHANISM OF SUBTLE OIL POOLS IN FAULT BASINS——TAKING THE JIYANG DEPRESSION OF THE BOHAIWAN BASIN AS AN EXAMPLE
Li Pi-long, ZHANG Shan-wen, SONG Guo-qi, XIAO Huan-qin, WANG Yong-shi
2004, 26(1): 3-10. doi: 10.11781/sysydz200401003
Abstract:
The critical controlling factors of subtle reservoir formation was researched systematically from the viewpoint of explorative practice for subtle oil pools in fault basins. The model of fault slopes controlling sandbodies in fault basins was built based on the analysis of the controlling effects of tectonic activities, which took faulting as the main behavior form, on reservoirs. By studying on the types and constitutional elements of transportation systems in fault basins, four types of transportation systems were pointed out, that is, the meshwork-carpet type, the T type, the ladder type and the fracture type. And their vertical and lateral multiple transportation relations were also described. After analysing on the effects of sedimentary facies zones and fluid potential on pool formation and their coupling relations, it was considered that sedimentary facies zones and fluid potential controlled pool formation in fault basins.
THE YANQI COMPRESSIONAL-THRUST RESIDUAL BASIN IN XINJIANG PROVINCE AND ITS OIL-GAS EXPLORATION
YUAN Zheng-wen, HE Ming-xi, SONG Jian-hua, GU Zhe, DU Jian-bo
2004, 26(1): 11-16. doi: 10.11781/sysydz200401011
Abstract:
In this article, the Yanqi Basin was divided into three structural deformation regions from south to north-southern decollement nappe region, central thrust folded region and northern strike-slip adjustment region according to the characteristics of inherited compressional inverse deformation getting strengthened from north to south in the Mesozoic Yanqi Prototype Basin during the Yanshanian and the Ximalayan periods. The compressional structures with NWW trend (close to EW trend) and the shear structures with NW trend crossed each other to form a "lozenge grid" structural pattern. The distribution features of secondary structural belts and local structures were controlled by this structural pattern. On the basis of structural and depositional distribution in the south and north depressions of the prototype basin, the zonation was further strengthened through paulopost reformation, and the north and south paleogeothermal field regions and the relatively independent petroleum systems were formed. In the residual basin, it created different oil-controlling structural combinations and different oil-gas accumulation patterns due to its three basic and unique deformation styles. Based on the reformation styles and pool-forming characteristics of the residual basin, it was predicted that the pool-forming units of "inheritance and regeneration" and "reformation and regeneration" in the northern depression were the favorable regions to discover reserves recently.
RESERVOIR CHARACTERISTICS AND THEIR CONTROLLING FACTORS OF THE CARBONIFEROUS KARASHAYI FORMATION IN TAHE OILFIELD
LI Yong-hong, YAN Xiang-bin, ZHANG Tao, ZHANG Sheng-gen, LIU Wen
2004, 26(1): 17-22. doi: 10.11781/sysydz200401017
Abstract:
The developing degree of reservoirs is the major controlling factor of hydrocarbon accumulation of the Carboniferous Karashayi Formation, an important oil reservoir bed in Tahe oilfield. The physical properties of reservoirs are mainly controlled by sedimentary microfacies and diagenesis. The lithology of branch channel sandbodies of braided river delta and medium-bedded tidal channel sandbodies are mainly medium-coarse-grained sandstone which develops intergranular pore-space and residual intergranular space, and have well accumulation features. The lithology of sandbodies of river mouth bar of braided river delta-front, interchannel, sand flat and sand bar of intertidal zones are mainly silt sandstone and fine-grained sandstone which have worse accumulation properties. In general, sandrocks are low-medium porosity and low-medium permeability reservoirs in this area. The sand-shale segment of the Karashayi Formation can be divided into five sand sets in depth, and the sandbodies of Ⅰ, Ⅱ sand set and Ⅲ sand set have well accumulation properties. The available reservoirs developed in three areas such as 3rd, 4th and 6th block of Tahe oilfield.
RECENT EXPLORATION ACHIEVEMENTS IN TAHE OILFIELD AND FUTURE EXPLORATION TENDENCY
HE Fa-qi, YU Ren-lian, HAN Zhen-hua
2004, 26(1): 23-27. doi: 10.11781/sysydz200401023
Abstract:
Started in the 1980s, the exploration in Tahe oilfield, Tarim Basin, has experienced four stages and made great achievements in marine facies oil and gas. Thanks to the recent exploration achievements, the oilfield scale has been enlarged. Furthur exploration tendency is put forward based on the analysis on these results.
ANALYSIS OF RESERVOIR FORMATION PERIODS, THE JIANGLING DEPRESSION OF THE JIANGHAN BASIN
LU Ming-guo, TONG Xiao-lan, WANG Bi-jin
2004, 26(1): 28-30. doi: 10.11781/sysydz200401028
Abstract:
Based on the guidance of petroleum system theory and oil-source rock correlation, there are 2 known petroleum systems in Jiangling Depression: upper Shashi formation-lower Xinggouzhui formation and Qian-jiang formation. The major period of reservoir formation for the former one was in the time of sedimentation of Qianjiang-Jinghezhen Formation, after which, it was modified. The petroleum system is characterized by multiple horizons of contemporaneously formed reservoirs because the extensively developed faults act as the important pass in hydrocarbon transmission system. Therefore, the exploration strategy in the depression should be focused on both the primary and the secondary hydrocarbon reservoirs and pay some attention to the upper Xinggouzhui formation, Jingsha formation, Qianjiang formation. Qianjiang formation petroleum system belongs to immature-premature petroleum system, which should be the new exploration area.
TECTONIC VARIATION CHARACTERISTICS AND CONTROLLING FUNCTION IN THE EASTERN PART OF THE LINQING DEPRESSION
LIU Zhong-quan, QIU Lian-gui, ZHOU Gui-qin
2004, 26(1): 31-34. doi: 10.11781/sysydz200401031
Abstract:
Using the principle of tilt variation, this paper analyzed the structures in the eastern part of the Linqing Depression, and summarized the basic structural characteristics of caprock sequences in the Paleogene and the controlling function of tilt variation to deposit. The research showed that the tilted fault blocks were the primary structure units in the basin and tilt variation not only controlled the evolution of the basin but also affected the development of paleogeomorphology in source areas. In the meantime, they also played an important role in controlling the types, distuibution and evolution of sedimentary systems in the basin. The fault troughs and the down slops close to the master controlling fault are the favorable positions for the development of oil-generating sags, while the up slopes and fault ridge areas far away from the fault are the main direction areas of hydrocarbon migration.
ANALYSIS OF RESIDUAL PORE FLUID PRESSURE IN THE TERTIARY OF THE XIHU DEPRESSION, THE DONGHAI SEA
LI Hai-hua, CHEN Yong-feng, LIU Jian-ning, LU Shu-e
2004, 26(1): 35-39. doi: 10.11781/sysydz200401035
Abstract:
The Tertiary drilling, logging and seismic interval velocity data from the Xihu Depression of the Donghai Sea were used to calculate the residual pore fluid pressure of hydrocarbon source layers. Based on the pressure analysis, the residual pore fluid pressure field of hydrocarbon source layers was established in order to approach the direction of hydrocarbon preliminary migration.
STUDY ON THE MECHANISMS FOR PRESERVING ANOMALOUSLY HIGH POROSITY IN DEEP BURIED SANDSTONE RESERVOIRS
ZHOU Dong-sheng, LIU Guang-xiang, YE Jun, JIA Cun-sha
2004, 26(1): 40-46. doi: 10.11781/sysydz200401040
Abstract:
Following up the late progresses on deeply buried sandstone in overseas petroliferous basins, and based on the origin and controlled factors of anomalously high porosity in deep burial reservoirs, the authors discussed, taking the Chuanxi sag in Sichuan basin for the best scenario, that the preserving mechanisms of intergranular porosity in mid to deep burial sandstone intervals, and indicated that the primary conservation mechanisms of intergranular porosity in Shaximiao formation are as follows: development of chlorite coating, early petroleum emplacement and shallow development of fluid overpressure.
APPLYING HYDROCARBON EXPELLING INTENSITY TO PREDICT OIL-BEARING POTENTIAL OF THE GLUTENITE FAN IN DEEP SAG STAGE
SUI Feng-gui, LUO Jia-qiang, CAO Jian-jun
2004, 26(1): 47-52. doi: 10.11781/sysydz200401047
Abstract:
Lithologic oil reservoir of the conglomerate fan-body developed in deep sag stage is the important target of oil-gas exploration in the mid-later term exploration in petroliferous basin, and it's oil-bearing potential is mainly dependent on the hydrocarbon expelling intensity of effective source rocks, the reservoir condition of gravel-sand fan-body and the result of their inter-action. It is found that the oil-gas full-up degree of fan-body has important relativity with the hydrocarbon expelling intensity, and it's accumulation effect is mainly affected by the reservoir condition if there is enough oil-gas resource in deep Dongying sag. The gravel-sand fan-body of displacement efficiency index over 15% and the hydrocarbon expelling intensity over 20×104t/km2is prone to form reservoir of high oil-gas full-up degree, and that the sand body of thickness over 2m and porosity over 12% is suitable for forming reservoir. The method has been applied to the oil-gas exploration of the gravel-sand fan-body in deep Dongying sag stage and has obtained better effect, Therefore it can be used to guide the exploration of lithologic oil reservoir in deep sag stage of continental basin.
PRACTICALITY OF TRACING OF LITHOSTRATIGRAPHICAL BOUNDAY FOR STEP BY STEP EXPLORATION AND DEVELOPMENT——AN EXAMPLE AT WESTERN CLINOTHEM OF LIAOHE SUB-BASIN
OUYANG Wen-sheng, CAO Dai-yong, DONG Qiang, ZHANG Jian-guo
2004, 26(1): 53-57. doi: 10.11781/sysydz200401053
Abstract:
The exploration of sedimentary basins generally undergo stages of reconnaissance survey, detailed investigation and step by step exploration development, and different methods for sequence correlation, such as biostratigraphy, chronostratigraphy, tectono-stratigraphy, seismic stratigraphy and sequence stratigraphy and so on, can be used. During stage of step by step development of an oilfield, the most important thing is the determination of lithostratigraphic boundary.The stratum boundary of terrestrial sediments on lateral accretion was at all time cross with time definition, but we may ignore its influence. The main point for the study of sequences is the lithostratigraphical boundary and its spatial distribution in the last stage of development.
RESERVOIR CHARACTERIZATION OF DONG Ⅲ FORMATION, TANGJIAHE DEVELOPING AREA OF BEIDAGANG OILFIELD, HUANGHUA DEPRESSION
REN Bao-sheng, LU Feng-ming
2004, 26(1): 58-62. doi: 10.11781/sysydz200401058
Abstract:
Aimed at the main contradictions in oilfield development and the geological problems remaining to be resolved in oilfield production, this article describes the reservoir characteristics of Dong Ⅲ formation, through high-distinguish sequence correlation, microstructure research, microfacies division, flow unit research, permeability parameter changes after water flooding, and numerical simulatlon, etc. Dong Ⅲ formation is vertically subdivided into 10 time-strata units and 25 individual sand bodies. Through the research on micropore structure, percolation screen and interconnection, pore structure and flow units are subdivided. Reservoir heterogeneity and changes of permeability parameters are also studied. Eventually, the distribution pattern of residual oil is put forward based on the research accomplishments. Effective adjusting project is made combined with production development, and has gained economic benefit in field testing.
WAVE IMPEDANCE INVERSION AND ITS APPLICATION TO THE PREDICTION OF SUBTLE TRAPS
BAI Tao, XU Zhi-wei
2004, 26(1): 63-67. doi: 10.11781/sysydz200401063
Abstract:
By using wave impedance inversion seismic profiles combined with logging and core data, the sequences of the Qingshankou and the Yaojia Formation in the Songliao Basin were preliminary interpreted, nine sequences and twenty system tracts were identified, and the sequence stratigraphic framework of this region was established. Based on the interpretation of sequence stratigraphy, sedimentary microfacies and structures on wave impedance inversion seismic profiles, five types of subtle traps were found, that is, stratigraphic overlap traps, tectonic-lithologic traps, sandstone updip-pinchout traps, fault-lithologic traps and sandstone lens-shaped lithologic traps. Also, their distribution regularities in sequence stratigraphic framework were summarized.
OIL-BEARING CHARACTERISTICS IDENTIFICATION IN SURFACE SANDSTONES——TAKING CUOQIN, KEKEXILI, BIRU AND CHANGDU BASINS IN TIBET FOR EXAMPLE
XU Huai-xian, PU Xiu-gang, HAN De-xin
2004, 26(1): 68-72. doi: 10.11781/sysydz200401068
Abstract:
It is very important to find oil shows in surface samples for a new oil and gas exploration area. Rock-Eval, chloroform extract, fluorescence observation, and element analysis of filling matter in pores can be used to determine whether surface sandstone is oil-bearing .If the fluorescence exist and carbon content is 75% and O/C atom ratio is 0.5 in pore filling matter, the surface oil-bearing sandstone will be characterized qualitatively in Tibet area. Meanwhile, pyrolysis hydrocarbon content can be used to calculate original oil-bearing saturation. In Tibet area oil-bearing level originally was from oil saturated to oil-showing if original oil-bearing saturated is 45% and chloroform extract is 120×10-6. It was oil immersed to oil spot while oil-bearing saturation is 20%-45% and extracts is(60-120)×10-6.It was only oil trace if they respectively are<20% and<60×10-6. Surface oil-bearing sandstones have been found in 4 basins of Tibet, that is, 3 in Cuoqin, 4 in Kekexili, 3 in Biru, and 4 in Changdu basins. Among them the best is C163 sandstone in Cuoqin basin. The pyrolysis hydrocarbon is 28.36mg/g and saturation is 51.8% and chloroform extracts is 123×10-6. Finally, Cuoqin and Kekexili basins are considered as oil-bearing basins, and Biru and Changdu basin natural gas-bearing ones.
DETERMINATION OF DOUBLE FILLING RATIO OF MIXED CRUDE OILS IN THE ORDOVICIAN OIL RESERVOIR, TAHE OILFIELD
WANG Tie-guan, WANG Chun-jiang, HE Fa-qi, WANG Jun-qi, ZHU Dan, WANG Chuan-gang, XIE Ming-liang
2004, 26(1): 74-79. doi: 10.11781/sysydz200401074
Abstract:
Be aimed at oil filling conditions in reservoir and taking the Ordovician reservoir in Tahe Oilfield as an example, the authors attempt to conduct an artificial partitioning experiment of mixed crude oils by double filling into the reservoir using individual filling oils as the end-member of artificial mixed oil samples. By mains of data processing soft-ware in the GC working station, the GC peak area ratios R/U between resolved components and unresolved complex mixture (UCM) can be measured on the gas chromatograms of all artificial mixed oil samples, the conversion diagram of double filling ratios of subsurface mixed crude oils were established based on the correlation curve between the partitioning ratios of artificial mixed oil samples and their R/U values. Owing to the heavy biodegradation only on the early filled oil, the R/U ratios can also be measured on the GC of subsurface crude oil samples, which can characterize the double filling ratios of hydrocarbons in the mixed crude oils, and then the double filling ratios of subsurface crude oils were obtained from above-mentioned conversion diagram and the R/U values.
EVALUATION METHOD OF OIL SATURABILITY WITH GEOCHEMICAL PYROLYSIS DATA
SUI Shu-ling, LIN Cheng-yan, HOU Lian-hua
2004, 26(1): 80-83. doi: 10.11781/sysydz200401080
Abstract:
Different influence factors have different influence degree to the different components of geo-chemical pyrolysis degradation. In this paper, the correction models of light, middle and heavy components ard sample weight, porosity and volume were established from the view point of influence mechanism. After correcting geochemical pyrolysis degradation data and getting accurate residual hydrocarbon content and gross hydrocarbon quantity, the evaluation models of oil saturability were built. A set of perfected methods to correct data, obtain oil density and residual hydrocarbon content and evaluate oil saturability were formed. The oil saturability of 32 layers in 21 wells with different reservoirs, levels and oil properties was evaluated. The results were very close to those from sealed core analysis.
SENSITIVITY EXPERIMENTAL STUDY AND ITS MECHANISM ANALYSIS OF RESERVOIRS IN THE THIRD MEMBER of THE SHAHEJIE FORMATION, GAOSHANGPU OILFIELD
CHANG Xue-jun, YIN Zhi-jun
2004, 26(1): 84-88. doi: 10.11781/sysydz200401084
Abstract:
The third member of the Shahejie Formation in Gaoshangpu oilfield is a set of fan delta deposition, which is characterized by bad physical properties and abundant clay mineral. As a result, its development effects were low. Reservoir sensitivity was studied in this paper through the core flow experiment. The results showed that the reservoir possessed strong velocity sensitivity, water sensitivity, alkali sensitivity and poor salt sensitivity. Reservoir sensitivity is a main factor to influence development effects. On the bases of rock composition and pore structure analysis, the formation mechanism of different sensitivity was analysed respectively, and the pertinent measures to control sensitivity in the course of development were brought out. The results of this paper is helpful to adjust reservoir development plans and made good effects in the experimental area .
THERMAL SIMULATION EXPERIMENT RESEARCH OF SINGLE MACERAL IN COALS WITH A WATERED PRESSURE VESSEL-AN EXAMPLE OF BROWN COAL IN THE YIMIN FORMATION OF THE HAILAR BASIN
HE Wei-gang, JIN Kui-li, HAO Duo-hu
2004, 26(1): 89-93. doi: 10.11781/sysydz200401089
Abstract:
In this paper, the thermal simulation experiment with watered pressure vessel was used to study the organic macerals in coals of the Yimin Formation (J3) of the Hailar Basin. The experiment results showed that desmocollinite was the most important hydrocarbon-generating source material with the main hydrocarbon-generating stage of 270-330℃ as well as the maximum liquid hydrocarbon yield of 19mg/g and gaseous hydrocarbon yield of 256mL/g, the main hydrocorbon-generating stage of sporinite was 300-380℃ with its maximum liquid hydrocarbon yield of 40mg/g and gaseous hydrocarbon yield of 265mL/g, and fusinite yielded hardly liquid hydrocarbon with its maximum liquid hydrocarbon yield below 2mg/g even at 300℃ and its gaseous hydrocarbon yield of 120-160mL/g. Compared with the water-free thermal simu-lation method, the peak hydrocarbon generation temperature of this method dropped obviously, commonly about 50-100℃.
APPLICATION OF ORGANIC INCLUSION TO STUDY OF HYDROCARBON MIGRATION AND ACCUMULATION-A CASE STUDY OF THE GAOYOU SAG IN THE SUBEI BASIN
LIU Xiao-ping, XU Jian, YANG Li-gang
2004, 26(1): 94-99. doi: 10.11781/sysydz200401094
Abstract:
The oil and gas maturity, stages of petroleum migration and accumulation of upper and lower petroleum systems of Gaoyou Sag in Subei Basin are determined based on the data of the occurrence, phase types and fluorescence of organic inclusion and the homogenization temperature of synchronous saltwater inclusion. The oil sources and its characters of the two petroleum systems are discussed and compared by geochemical analysis of organic inclusion compositions. The migration direction and accumulation mechanism of lower petroleum system in SN region are studied according to the biomarkers data of organic inclusion and its results is in accordance with that of the analysis of pyrrolic nitrogen compounds. So that such study provides a kind of more direct microscopic proof and method for hydrocarbon migration and accumlation. The successed case study also indicates that organic inclusion analysis has more wide prospect in the study of migration and accumulation in petroliferous basin.
APPLICATION OF QUANTITATIVE FLUORESCENCE ANALYSIS TO THE DISTINGUISHMENT OF OIL PROPERTIES-A CASE STUDY IN SHENGLI OILFIELD
CI Xing-hua, XIANG Qiao-ling, CHEN Fang-hong, SHI Xiao-mei
2004, 26(1): 100-102. doi: 10.11781/sysydz200401100
Abstract:
Based on the data of Shengli oilfield, the authors discussed the application of quantitative fluorescence analysis to the distinguishment of oil properties. Using the characters of fluorescence spectrograms, maximum peak values and corresponding wavelength position, oil properties can be distinguished qualitatively. And using the index of oil properties, we can confirm oil properties quantitatively.
STUDY OF FAULT SEALING BY THE 3-D PALEO-TECTONIC NUMERICAL SIMULATION
SHEN Chuan-bo, MEI Lian-fu, LIU Li-lin, ZENG Zuo-xun, TANG Ji-guang
2004, 26(1): 103-107. doi: 10.11781/sysydz200401103
Abstract(1757) PDF-CN(332)
Abstract:
Fault sealing is closely related to the function of stress. Therefore, we can study fault sealing through calculating the size of normal stress of fault plane, on the basis of considering overburden load and regional major compressive stress. The text discussed the approach to the 3-D tectonic numerical simulation of fault-sealing research by use of the MARC finite element analysis software of American's MSC software company, and cited an example-one fault in Yudong area. The results revealed that the deep and slant angle of fault plane affected fault sealing. And they also expressed that the approach of the 3-D tectonic numerical simulation can not only study the fault-sealing history, but also evaluate the sealing of different layers and different parts.
DEVELOPMENT OF THE CORE JOURNALS OF OIL AND NATURAL GAS INDUSTRY CATEGORY (TE)
LI Li
2004, 26(1): 108-110. doi: 10.11781/sysydz200401108
Abstract:
The developments of the core journals of oil and natural gas industry category (TE) in the 1st, 2nd and 3rd editions of "A Guide to the Core Journal of China", and the development of the assessment indices are introduced in this paper. The Core Journal Table is also presented. The development of the 4th edition of the "A guide to the Core Journal of China" is in progress.