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01 August 2010, Volume 31 Issue 4 Previous Issue    Next Issue

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Lacustrine Source Rock Occurrence and Its Petroleum Reservoir Distribution of Paleogene Fault Basins in Offshore China and Southeast Asia KANG An, YANG Lei 2010, 31 (4):  337-340.  Abstract ( 90 )   PDF (608KB) ( 586 )   Save The hydrocarbon-generating amounts from lacustrine source rocks mainly distributed in the fault basins of the Paleogen in offshore China and Southeast Asia account for 95% and 48% of the total petroleum resources in these areas, respectively. This paper presents the distributing features of seven fault basins' source rocks and their reservoirs in such areas and suggests by correlation that there exist two distinct models of source rock distribution: one is Bohai Bay basin model characterized by deep lacustrine shale of big thickness and wide distribution; the other is Asri-Central Sumatra basin model by shallow lacustrine shale of small thickness and narrow distribution. Based on these, the spatial combination relationship between the source rock distribution and the existing oil-gas fields is analyzed, and the features of source rock distribution and the reservoirs are revealed. References | Related Articles | Metrics

Impact of Pack Bitumen on Reservoir Quality—An example from Santai-North Santai in Junggar basin CHEN Shi-jia, YANG Guo-ping, LU Jun-gang, LU Lin-chao, CHEN Xue 2010, 31 (4):  341-343.  Abstract ( 72 )   PDF (420KB) ( 223 )   Save A large amount of bitumen and heavy oil with high density are found in the Triassic and Jurassic reservoirs in Santai-North Santai area in eastern Junggar basin. They filled into the reservoir pores, occupied the megapores, reduced the porous connection rate, caused the post-generating crude oil to enter the pores with difficulty, hence it is difficult to form larger-scale and higher-yielding oil reservoir. The reservoir property contrast between before and after the organic solvent extraction indicates that the porosity of 9 samples adds to 21.5%, averaging about 13.4%; the permeability of 7 samples adds to 121.50×10-3μm2, averaging about 31.99×10-3μm2. It is pointed out that it should keep away from the reservoir with high amount of bitumen as far as possible to find high-yielding oil reservoirs in the future, in addition to considering structural factors, integrated with sedimentary facies and reservoir research results. References | Related Articles | Metrics

The Cambrian Sequence and Lithofacies Paleogeography in Bachu Uplift in Tarim Basin ZHU He, LIU Jia-duo, MENG Wan-bin, YANG Yong-jian 2010, 31 (4):  344-348.  Abstract ( 85 )   PDF (639KB) ( 296 )   Save Based on the sequence interface identification and sedimentary facies analysis, the Cambrian in Buchu uplift in Tarim basin can be divided into 2 second-order sequences (SS1 and SS2) and 14 third-order sequences. Each second-order sequence consists of transgressive system tract (TST) and highstand system tract (HTS). It is indicated that during the development of SS1-TST, a set of deepwater basin-facies deposit develops in this area with crust subsidence, relative sea-level quick raising; during the development of SS1-HST, the regional sedimentary framework transforms from basin to restricted platform and finally enters into open and evaporating environment influenced by lowing sea level, restricted water cycle and dry-hot climate, dominated by gypsodolomite and gypsite. Thus a set of important regional dense cap rocks is formed; as the development of SS2, a large scale of sea-level ascending-descending cycle occurs, as a result a framework of open platform-restricted platform-open platform is shaped. References | Related Articles | Metrics

The Coal-Bed Mathane Accumulation Factors and Explorative Target in Eastern Junggar Basin LIU De-guang, LUO Xiao-jing, WAN Min, GONG Hong-yan 2010, 31 (4):  349-351.  Abstract ( 108 )   PDF (260KB) ( 332 )   Save Based on the latest information, the macro-distribution, coal rank, coal quality and gas-bearing nature of Jurassic coals in eastern Junggar basin are analyzed comprehensively. The main controlling factors of coal-bed methane accumulation in this area are clarified as coal-bed burial depth, coal rank, coal quality and preservation condition, and the most important ones are the depth of weathered zone of methane and coal rank. Consequently, the enriched areas and horizons of coal-bed methane in eastern Junggar basin are identified, namely Bogeda piedmont, Badaowan formation in Jimusaer sag and coal bed of Xishanyao formation in Wutongwozi sag. Considering the factor of depth, the Bogeda piedmont will be the main target for exploration in this area in the future. References | Related Articles | Metrics

Natural Gas Origin and Its Accumulation Feature in Dibei Swell in Junggar Basin LI Lin, XIA Hui-ping, CHEN Shi-jia, LU Jun-gang, XIA Qing 2010, 31 (4):  352-355.  Abstract ( 96 )   PDF (340KB) ( 245 )   Save Kelameili gas field with reservoirs of about 100 billion cubic meters was found in Dinan swell, but in Dibei swell just small scale gas pool is found now and no great breakthrough has been made. The comprehensive evaluation of source rocks indicates that its Carboniferous source rocks with wide distribution, high organic matter abundance and high maturity should be of more intensive hydrocarbon generation potentials. The source rocks of Dishuiquan formation of Lower Carboniferous are dominated by II2-III organic matter types, while Batamatineishan formation of Upper Carboniferous by III type. The study suggests that natural gas in Dibei swell should come from the Carboniferous source rocks characterized by high revolution degree and mixed with autochthonous gas or lowmaturity gas from Jurassic coal measures near the reservoir. It is this that brings about heavier ethane carbon isotope and lighter methane carbon isotope in Jurassic gas. The source rocks of upper part of the Carboniferous in Dibei swell are in low maturity, reflecting its hydrocarbon should come from the source rocks in the Carboniferous in Dibei swell deep and Beimian sag deep. References | Related Articles | Metrics

Paleocurrent and Sands Extending Directions of Badaowan Formation in Well Tai-13 Area in Eastern Junggar Basin JIN Zhen-kui, WANG Zhao-feng, GU Jun-feng, SUN Xiao-fang, DAI Xiong-jun, WANG Jian-xin 2010, 31 (4):  356-357.  Abstract ( 91 )   PDF (209KB) ( 279 )   Save Well Tai-13 area in North Santai field in Junggar basin is located in east part of FuDONG fault belt near Bogeda mountain, belonging to piedmont thrustfault belt. At present, oil is found in Badaowan formation, showing good prospect for petroleum exploration in this area. However, this area is characterized by complex structure, poor seismic data quality, few drilling well, difficult prediction of glutenite reservoir extension direction, so these give rise to big barriers for well location deployment and effective development in this field. Based on fewer drilling data, previous researchers plotted the sand body isopach map, predicting that its paleocurrent direction was from the south to the north, the source came from Bogeda mountain in its south. According to these, integrated with vicinal outcrop studies, drilling data and regional geologic setting, the paleocurrent direction and sand body extending direction are studied in this paper. The results show that in period of Badaowan formation in Well Tai-13 area, the paleocurrent direction was trending from NE to SW, the channel sands extending from NE to SW; the source should come from Qitai swell in eastern Junggar basin. References | Related Articles | Metrics

Stratigraphic Erosion Recovery of the 2nd Episode of Himalayan Movement in Jiyang Depression LIU Shi-lin, LIN Ge, ZHENG He-rong, WANG Yi, YUN Jin-biao, GAO Shan-lin, XU Lei 2010, 31 (4):  358-360.  Abstract ( 100 )   PDF (292KB) ( 161 )   Save The eroded strata recovery technologies such as sonic logging, fission track and strata correlation are used to recover the erosion thickness of the 2nd episode of Himalayan movement in Jiyang depression of Bohai Bay basin, and the result reveals that the denudation thickness becomes smaller from uplifts to slopes and to subsidence centers of sags. The erosion phenomena are more serious in DONGying sag and Huimin sag of southern Jiyang depression than in Chezhen sag and Zhanhua sag of northern Jiyang depression. The horizontal differences of denudation thickness suggest that the structural features at the Late Paleogene were characterized by the swellsag alternating and the high in the southwest and low in the northeast within Jiyang depression. References | Related Articles | Metrics

Characteristics and Favorable Reservoir Facies Belt of Sublacutrine Fan of Nantun Formation in Beier Sag, Hailaer Basin XU Xian-sheng, WANG Jing-xin, YANG Ting, WANG Wen-di, ZHANG Lei, WANG Zhe 2010, 31 (4):  361-364.  Abstract ( 84 )   PDF (484KB) ( 265 )   Save The Nantun formation of Lower Cretaceous in northwestern Beier sag in Harlaer basin develops typical sublacutrine fan deposit. According to the core, well logs and grain-size analysis data, the sublacutrine fan located in the back slope and near paleohigh can be divided into three subfacies of inner, middle and outer fans and six microfacies in this region. The great height difference of geography formed by the regulatory faulting activity in the back slope allows this area to develop large scale alluvial fan-fan delta-sublacutrine fan deposit system by the way from provenance to lacustrine basin. The mudstone in the semi-deep lacustrine-deep lacustrine near the sublacutrine fan is not only source rock, but also preferable cap rock. So the conglomerate and sandstone in the fan is favorable to form lithologic trap. The sand-body developing belt of braided channel microfacies in middle fan is the mid-porosity and mid-low permeability reservoir facies belt and favorable for petroleum exploration. References | Related Articles | Metrics

Sedimentary Characteristics of Yingshan Reefs of Middle Ordovician in Xike'er Area, Tarim Basin ZHOU Gang, ZHENG Rong-CAI, LUO Ping, LIU Wei, SONG Jin-min 2010, 31 (4):  365-368.  Abstract ( 81 )   PDF (537KB) ( 262 )   Save The reefs (bioherm) or baffle reefs were discovered in upper Yingshan formation of the Middle Ordovician. The reef-building organism composes of Calathium, calcium algae, bryozoan, sponge, etc., dominated by Calathium. The reefs occur on the uplift of open platform, and were formed in regressive background without exposure signs and the division of reef front, reef behind and reef flank, but can be divided into reef base, reef core and reef cover. Reef base is dominated by echinoderm grainstone; reef core by Calathium bafflestone, algae-Calathium bafflestone, fractures, hole-groove filled substance, and reef cover by sparite calcarenite. The reefs undergo five stages of evolutions and develop two ecological communities. References | Related Articles | Metrics

Gas-Generating History from Middle-Lower Jurassic Coal Measures in Southern Margin of Junggar Basin LI Ji-jun, LU Shuang-fang, XUE Hai-tao, HU Guo-yi, LIU Wen-lei 2010, 31 (4):  369-370.  Abstract ( 71 )   PDF (244KB) ( 357 )   Save The process of natural gas generation from the Middle-Lower Jurassic coal measures in the southern margin of Junggar basin is simulated with chemical kinetic method by taking the coal-derived gas of Xishanyao formation as an example. The results indicate that the gas generation occurred mainly in Yanshan movement period, accounting for about 80% of the final gas amount, dominated by the period of Cretaceous. Corresponding to the most natural gas generation, the formation of the first-line anticlinal traps in Yanshan period is very significant. Moreover, the Himalayan movement decides the reservoir-forming condition of natural gas in this area. On the one hand, the tectonic adjustment on the first line anticlinal traps (including the continuous conservation of oil and gas in primary reservoirs and the migration toward secondary reservoirs) decides the resource perspective of natural gas in this area to a great extent. On the other hand, the second and third line anticlinal traps formed during the movement can accumulate the natural gas from the late pyrolysis of kerogen and the second cracking of crude oil. References | Related Articles | Metrics

Fractal Characters of Oil Reserves in Spatial Distribution in Raoyang Sag FENG Zhen-DONG, DAI Jun-sheng, LIU Jing-DONG 2010, 31 (4):  372-374.  Abstract ( 85 )   PDF (301KB) ( 136 )   Save Based on the classification of reservoir grade, the reserves fractal curves of 201 reservoirs in Raoyang sag are studied. The results indicate that in future exploration it is difficult to find reservoirs with more than 112×104t reserves; the reservoirs with (28~112)×104t reserves are of certain exploration potentials, and most reservoirs with less than 28×104t reserves are to be proven. By calculating the fractal dimensions of reserves of pre-Paleogene, Shahejie formation, DONGying formation and Neogene reservoirs and counting fractal eigenvalues of reservoirs of every sequence, it is suggested that Shahejie formation is of the greatest exploration potential, followed by DONGying formation, Neogene and pre-Paleogene. However, there are more opportunities to find reservoirs with more than 30 ×104t reserves in pre-Paleogene than that in Neogene. By comparison among fractal characters of spatial distribution of all reservoirs, pre- Paleogene reservoirs and Shahejie reservoirs, it is found that the whole fractal dimension (D) is much greater than layered fractal dimension, so the size of D only reflects the oil-bearing area, but it can not represent the size of reserves directly. References | Related Articles | Metrics

Gypsolyte Sedimentary Environment of Upper Jurassic-Lower Cretaceous in Shenglihe Area in Northern Qiangtang Basin WU Tao, XIONG Xing-guo, YI CHENg-xing, BAI Pei-rong, HE Yong-zhong, LIU Zhen-CAI 2010, 31 (4):  376-378.  Abstract ( 123 )   PDF (271KB) ( 353 )   Save In 2007, a set of gypsolyte strata with depth of 196 m was found above Suowa formation of Upper Jurassic in Shenglihe area in northern Qiangtang basin of Tibet. This study suggests from analyses of top-bottom lithology and gyprock crystal forms, interbed and sedimentary assemblage that such strata are characterized by coast salt lake deposit. Its discovery could provide good cap rock for hydrocarbon accumulation in the Mesozoic northern Qiangtang basin. References | Related Articles | Metrics

Dense Limestone Barrier Distribution of Fractured-Vuggy Carbonate Reservoirs ZHAO Min, HOU Chaohui, LIU Li 2010, 31 (4):  379-381.  Abstract ( 85 )   PDF (219KB) ( 384 )   Save Tahe field is characterized by strong heterogeneity of the Ordovician carbonate reservoirs, complicated oil-gas-water relationship and complex reservoir type. The 3D geologic modeling has shown quantitative characterization of the pore, vug and fracture of the weathering crust within 300 m in the reservoir. But with in-depth development of Tahe field, it has been suggested there exist vertical dense limestone segments that play a role of barriers among the fractured-vuggy carbonate reservoirs. This paper conducts the correlation researches on well dense segment and interwell dense barriers by means of related geologic cognition and well logging, seismic and well performance data, by which the 3D model for dense limestone barrier is developed. This model can be helpful for evaluating the lateral connectivity of reservoirs and selecting the waterflood pattern, water shutoff measure and blocking interval. References | Related Articles | Metrics

Carbonate Dissolution of Lianglitage Formation in Southern Slope Break of Tazhong Area YOU DONG-hua, QIAN Yi-xiong, LI Zhong-quan, CAI Xi-yao, LI Hui-li 2010, 31 (4):  382-385.  Abstract ( 73 )   PDF (582KB) ( 259 )   Save Based on the data of the rock-configuration, cathodoluminescence, scanning electron microscope and energy spectrum of Lianglitage formation in Zhong-2 well located in the southern slope of Tazhong area in Tarim basin, the remaining pores and cavities in the cores are formed by the burial dissolution. And the pores and cavities are corroded and filled with the coarse calcite or dolomite formed by the carbonate mineral's solution and deposition in the burial condition. The 87Sr/86Sr ratio in the grainstone and calcite in the cavity at the base of Lianglitage formation is lower than that in the seawater at that time, but the 87Sr/86Sr ratio at the top of Lianglitage formation is higher than that in the seawater because the continental fragment (e.g. feldspar) is corroded. The burial cementation and dissolution are proved by the homogenization temperature and salinity of the two-phase saline inclusion of the late filling calcite vein and pore-filling calcite. References | Related Articles | Metrics

Fluid-Density Inversion of Shaximiao Gas Reservoir in Western Sichuan Area LI Shu-guang, XU Tian-ji 2010, 31 (4):  386-387.  Abstract ( 69 )   PDF (298KB) ( 156 )   Save The fluid-density changes from rich gas reservoir to water layer obviously, so it is a nice parameter of reservoir gas forecasting. This paper presents the method for calculating the fluid-density values of each reservoir using density logging and porosity data, according to the density-porosity least-square inversion method, calculated the fluid-density of reservoir in well. The inversed three dimensional fluiddensity results can be obtained based on the probabilistic neural network inversion method, and using the well fluid-density data and three dimensional seismic data. Application of this method to Shaximiao gas reservoir in a gas field of western Sichuan area has achieved very good results, providing important data support for reservoir prediction, gas-water identification and gas reservoir description in this area. References | Related Articles | Metrics

Application of Statistical Method to Quantitative Assessment of Natural Gas Resources—An example from the Jurassic-Cretaceous in middle part of the West Sichuan depression ZHOU Zong-ying, Ma Li-yuan 2010, 31 (4):  388-390.  Abstract ( 78 )   PDF (282KB) ( 167 )   Save According to the different exploration levels of J-K (shallow and middle strata)and Xujiahe formation(deep strata)in the middle part of West Sichuan depression, the pool size sequence method is selected to calculate the amount of natural gas resources of J-K, reservoir volume method to calculate the amount of natural gas resources of Xujiahe formation. The results show that natural gas geological conditions in this area are preferable and rich in natural gas resources, with the amount of natural gas resources in place of about 1.161×1012m3. At present, the resources proven degree is only 14.68%, revealing that it is in the early fast development stage for gas exploration as a whole, with huge gas resources potentials. This will be as a guide for further gas exploration deployment and the midand long-term development goal establishment. References | Related Articles | Metrics

Investigation Distance Formula for Wells in Parallel Flow Formation LI Chuan-liang, YAO Shu-ying 2010, 31 (4):  391-392.  Abstract ( 129 )   PDF (172KB) ( 247 )   Save The conventional formula for calculation of investigation radius of wells is deduced for vertical wells, which can only be applicable for radial flows rather than for parallel flows. By means of the flow theory in porous media and the production scheme of constant bottom-hole pressure of a production well, the concept of investigation distance of parallel flows is defined. Then the formula of investigation distance of parallel flow is deduced with the propagation theory of pressure pulse wave in formation. This formula can be used for situations of horizontal wells, parallel well patterns and channel strip sands, solving the problems of the pressure propagation scope and the distance of investigation in order to guide the production better. References | Related Articles | Metrics

Prediction of Compressibility Factor of Condensate Gas in Junggar Basin SHUAI Wei-zhi, MAO Xian-ping 2010, 31 (4):  393-395.  Abstract ( 92 )   PDF (246KB) ( 193 )   Save Eeleven calculating models are applied to calculating compressibility factor of condensate gas reservoir in Junggar basin and making a correlation of the results. The calculation model is found for early forecasting compressibility factor of both common natural gas reservoir and condensate gas reservoir. Also, the correction method of compressibility factor is found for AGA8-92DC model, HTP model, SHBWR model, SRK model and low-pressure Z-model. The calculated results show that the maximum average error is reduced to 0.92% from 5.64% with greatly increasing accuracy of such a prediction. References | Related Articles | Metrics

Determination of IPR Curves of Unsaturated Reservoir with One-Point Method HU Jian-guo, QU Xue-feng 2010, 31 (4):  396-398.  Abstract ( 101 )   PDF (202KB) ( 286 )   Save Based on Evinger-Muskat equation, using Fetkovich techique, the method for determination of IPR curve of oil well with onepoint method and prediction of well productivity variation in unsaturated reservoir is presented. The case study indicates the this method is correct and eqqective. References | Related Articles | Metrics

Effect of Injection Rate on Spontaneous Imbibition of Sandstone PENG Yu-qiang, HE Shun-li, GUO Shang-ping, HAN DONG 2010, 31 (4):  399-401.  Abstract ( 93 )   PDF (196KB) ( 316 )   Save The effect of brine injection rate on spontaneous imbibition behavior and recovery of sandstone is studied, and the ultimate recovery comparison between static imbibition and dynamic imbibition is conducted. The results show that with the increase of brine injection rate, the dynamic imbibition recovery increases and decreases, rapidly, and then tends to be stable, with mono-peak variation in oil recovery and brine injection rate. The fact that dynamic imbibition recovery is lower than static one indicates that spontaneous imbibition of sandstone needs enough time to full exert capillary imbibition in low permeability reservoir. So the injection rate should be low, and measures including intermittent and cyclic injection and production should be adopted in order to increase the spontaneous imbibition recovery. References | Related Articles | Metrics

The Factors Influencing Injection Profile of Water Input Well WANG Ji-qiang, SUI Yi-yong, YANG Wen-wen, YE Yin-zhu, MENG Zhao-juan, LI Yan-lai 2010, 31 (4):  402-403.  Abstract ( 81 )   PDF (154KB) ( 208 )   Save By choosing the possible influence factors for injection profile from geology and production, the analysis of correlation between the factors and the injection profile is made respectively. The result shows that the correlation between them is not purely ensured by functions. Prediction of the injection profile can not be conducted just by one of the factors but using non-linear method with multifactors such as permeability capacity, permeability contrast, oil-water well connected condition, sand type, connected oil wells, connecting well spacing and stimulation measures. The case study shows that this method is effective in practice. References | Related Articles | Metrics

Determination of Mass Concentration of Crude Oil with Piecewise Function of Synchronous Fluorescence Spectrum XIAO Zhuan, DAI Jia-CAI 2010, 31 (4):  404-405.  Abstract ( 93 )   PDF (167KB) ( 194 )   Save The conventional two-dimensional emission spectrum shows a limited range of crude mass concentration that is directly determined from 0 to 4×10-2g/L. This paper proposes a new method suitable for ranges from 1.22×10-4g/L to 3.0 g/L by piecewise function of synchronous fluorescence spectrum to determine the crude mass concentration. The mass concentration function forms matched by this method are simple, with not so much calculation, but high accuracy. References | Related Articles | Metrics

The Effect of Confining Pressure on Rock Permeability Measurement HOU Guo-qing, DENG Li-zheng, LI Qing 2010, 31 (4):  406-407.  Abstract ( 83 )   PDF (131KB) ( 383 )   Save In this paper, the permeability values of 13 rock samples with different confining pressures are tested. The experimental results show that applied confining pressure of 1.5 MPa is enough to seal the rock samples; there is a falling trend of permeability values from the same rock sample with an average decline up to 26.27% when the confining pressures are within the upper and lower limit of industry-standards suggested pressures; permeability decreasing amplitude is related to the original permeability of rock samples, the effect of confining pressure on high-permeability rock samples can be ignored, but that on low-permeability ones is obvious, and the errors should be considered when using these data; permeability decreasing amplitude is independent of lithology. References | Related Articles | Metrics

Streamline Numerical Well-Testing Interpretation Model for Horizontal Wells and Its Application WU Ming-lu, YAO Jun, JIA Wei-xia, ZHANG Kai 2010, 31 (4):  408-412.  Abstract ( 97 )   PDF (583KB) ( 290 )   Save A streamline numerical well-testing interpretation model for horizontal wells is developed based on the percolation characteristics of horizontal wells, including two mathematical models, one is the percolation mathematical model for the production period and the other is streamline mathematical model for the testing period. In both of the models, the different flow shapes in wellbores of horizontal wells can be taken into consideration besides the influence of factors such as reservoir heterogeneity, production history, wateroil two-phase flow, complex well pattern and complex boundary, etc. Reservoir parameters can be obtained by solving the model with streamline method and using well test auto-matching method based on genetic algorithm. A new well test interpretation method for horizontal wells is formed suitable for medium-high water cut stage reservoirs. The pressure response characteristics of streamline numerical well-testing interpretation model for horizontal wells is achieved by calculating an ideal inverted five-spot horizontal well reservoirs model associating with the streamline distribution configuration analysis. Streamline numerical well testing interpretation software is developed. The case study indicates the practicability of the software and the model. References | Related Articles | Metrics

Structure of Carboniferous Volcanic Rocks in LuDONG Area with Electric Field Sounding Technique SUO Xiao-DONG, DONG Wei-bin, HUANG Qing-wei 2010, 31 (4):  413-415.  Abstract ( 94 )   PDF (418KB) ( 195 )   Save Electric field sounding is a new technique for electric prospecting by means of high power and artificial field source shot with high resolution and accuracy. Its profile can be applied to clear reflection of the Carboniferous structures in LuDONG area in Junggar basin. There exist two sets of volcanic sequences in upper and lower parts of the Upper Carboniferous, sedimentary stratum in the middle. The lateral variation of lithology within the volcanic sequences and the development of their volcanic structures are also reflected in it. The study shows that in different areas the Carboniferous is in different degrees of remains which cause that obvious differences occur in corresponding electric structure of volcanic rocks. It is suggested that the electric field sounding technique as an important supplement process is of good applicable results for the Carboniferous explorative domain in North Xinjiang. References | Related Articles | Metrics

Application of Wavelet Transform-Based Spectral Decomposition Technique to Seismic Model Interpretation QI Yu, LIU Zhen, WEI Jian-xin, DI Bang-rang, LI Juan 2010, 31 (4):  417-418.  Abstract ( 108 )   PDF (300KB) ( 327 )   Save Spectral decomposition technique can be used to accurately calculate the reservoir thickness according to different tuning amplitudes in seismic reflection corresponding to components of different frequencies. Wavelet transform is an important method for spectral decomposition. Application of it to a seismic geophysical model can not only effectively predict the reservoir thickness, but also describe the lateral distribution characteristic of reservoir and the evolution of sedimentary facies. References | Related Articles | Metrics

Application of Compositional Model to High Volatile Oil Reservoir—An example from Bohai Bay S field ZHANG Hong-you, WANG Yue-jie, LEI Yuan, MA Kui-qian, CHAI Shi-chao 2010, 31 (4):  420-422.  Abstract ( 87 )   PDF (291KB) ( 327 )   Save A volatile oil reservoir is different from a black oil reservoir for its gas and liquid components change with pressure by natural depletion process. It is necessary to select more accurate compositional model to simulate the volatile oil reservoir. This paper matches the PVT experimental data from high volatile reservoir in Bohai Bay S field, based on which simulates the whole process of natural depletion of this field with the compositional model. And the result of the compositional model is compared with that of the black oil simulator. References | Related Articles | Metrics

Application of Partial Correlation Analysis to Oil Recovery Rate Influencing Factor Analysis TANG Zi-Chang, CHENG Lin-song, LI Chun-lan 2010, 31 (4):  423-425.  Abstract ( 68 )   PDF (221KB) ( 216 )   Save In order to clarify the major affecting factors of oil recovery rate in different exploitation phases, this article analyzes uses the partial correlation analysis method to analyze the influences of permeability, viscosity, reserves abundance, well spacing density and injector-producer ratio on the oil recovery rate by using performance data from domestic 26 reservoirs. The result indicates that the permeability, viscosity and reserves abundance mainly affect the early oil recovery rate, seldom influence the late one; the well spacing density and injector-producer ratio mainly affect the late oil recovery rate compared with the early one. References | Related Articles | Metrics

P-Wave Velocity Analysis Method Based on HTI Media Theory MA Zhao-jun, TANG Jian-ming 2010, 31 (4):  426-428.  Abstract ( 97 )   PDF (429KB) ( 296 )   Save With the continuous improvement of exploration precision, the isotropic media theory can no longer meet the current velocity analysis and normal moveout (NMO) processing of wide-azimuth and far-offset seismic data. Using wide-azimuth P-wave seismic data, velocity analysis method based on horizontal transverse isotropy (HTI) media theory is discussed in this paper. According to anisotropic theory, velocity azimuth anisotropic elliptic equation has been obtained. The least-square fitting method has been applied to solve elliptic equation parameters. The azimuth velocity has been calculated by elliptic equation and used for NMO processing. The method has been applied to process the wide-azimuth seismic data in HXC-GMZ area in western Sichuan successfully. References | Related Articles | Metrics

Petroleum Geology Theory with Chinese Features—An important role of volcanic activity to formation of domestic oil-gas fields GUO Zhan-qian, KANG Da-CHEN, WANG Zhuo-zhuo 2010, 31 (4):  429-433.  Abstract ( 111 )   PDF (380KB) ( 391 )   Save With more and more requirements for oil-gas resources in China, the current petroleum geology theory has not met the need of domestic petroleum geologic exploration. In such a case, proposing a looking-for-oil theory based on China's geologic features is especially important. Chinese continental crust is the most active in global volcanic activities which have remarkably stimulating effects on "basin formation", "hydrocarbon generation" and "hydrocarbon accumulation" that are three key propositions in petroleum geology. Some basic problems of petroleum geology about volcanic activity are generally discussed in this article so that could enrich and develop Chinese petroleum geology theory. References | Related Articles | Metrics

Discussion on Formation Mechanism of n-Alkane Peaks in Order Series in Crude Oil ZHOU Yan-ru 2010, 31 (4):  434-439.  Abstract ( 97 )   PDF (403KB) ( 261 )   Save The effects of the chemical turbulence of the negentropy and self-organization periodic oscillations and aperiodic alternating appearance can be caused by the material exchange and energy exchange among the absorbed substances of clay mineral crystal laminas, such as metal cations, water molecules and organic matters, etc. in the source rocks in open complex systems of nonequilibrium. This brings about splitting and reassembly of organic matter and forms a new hydrocarbon with n-alkane peaks in order series. References | Related Articles | Metrics

Discussion on Screening Conditions for Steam Huff and Puff in Super Heavy Oil Reservoirs DU Dian-fa, GUO Qing, HOU Jia-gen 2010, 31 (4):  440-443.  Abstract ( 112 )   PDF (341KB) ( 209 )   Save Steam huff and puff is the major technology for the development of heavy oil reservoirs now. But for the super heavy oil reservoirs whose oil viscosity is far larger than 5×104mPa·s, the screening conditions are still unclear. According to the present oil price, the periodic ultimate oil-steam ratio of single well, the ultimate oil production of single well and other economic indices are studied based on input and output balance principle. Then screening criteria for steam huff and puff are discussed by simulation. The simulation results show that the super heavy oil reservoir is suitable for steam huff and puff when the oil viscosity is less than 50×104 mPa·s, the effective thickness is lager than 8.5 m, the net-gross thickness ratio is larger than 0.4, oil saturation is lager than 50%, porosity is larger than 20%, permeability is larger than 500×10-3μm2, and the Kv/Kh ranges from 0.1 to 0.5. The determination of these screening conditions will be an important guiding significance for steam huff and puff in super heavy oil reservoirs. References | Related Articles | Metrics

Petroleum Geology and Exploration Potential Analysis in Bonaparte Basin PANG Lin-an, WANG Zhi-xin, ZHU Guang-hui, KANG Hong-quan 2010, 31 (4):  444-446.  Abstract ( 120 )   PDF (258KB) ( 231 )   Save Bonaparte basin underwent the stages of pre-rifting or craton, northwest trending rifting, northeast trending rifting and passive continental margin development, forming the major tectonic units such as the Paleozoic northwest trending Petrel sub-basin and the Mesozoic northeast trending Vulcan sub-basin, Malita graben, Sahul platform, Ashmore platform and Londonderry uplift. Four chief source rocks in this basin are developed, namely Lower Carboniferous Milligans formation, Permian Keyling-Hylandbay formation, Lower-Middle Jurassic Plover formation and Upper Jurassic Lower Vulcan formation, dominated by Plover reservoir, which is of favorable sourcereservoir- cap rocks assemblage. In the plane, petroleum has the feature of wreath-sag distribution. Crude oil is mostly distributed in Vulcan sub-basin, Petrel sub-basin and Laminaria uplift, whereas Sahul platform and Malita graben contain bulk of the natural gas. By the end of 2008, 1.53×108m3 oil (including condensate) and 6 790×108m3 gas had been proved in this basin. The analysis of petroleum geology shows that Vulcan sub-basin and Malita graben are the favorable tectonic units and the regional unconformity and stratigraphic and lithologic traps are the most promising play. References | Related Articles | Metrics