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01 October 2007, Volume 28 Issue 5 Previous Issue    Next Issue

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A Microphysical Interpretation for Stereoisomer Rearrangement of Biomarker Compound ZHOU Yan-yu 2007, 28 (5):  523-528.  Abstract ( 104 )   PDF (283KB) ( 282 )   Save In this paper, the stereoisomer rearrangement of biomarker compound for the exclusive reaction form the electronic off-domain to the out-proton magnetic rotation is interpreted in the sedimentary system in terms of the micro-particle wave motion and the molecular orbital theory. First of all, the theoretic basis for the stereoisomer rearrangement of biomarker compound is illustrated, and then the corresponding relations between the sterane/terpane stereoisomer rearrangement and maturity, as well as the polarity/non-polarity and petroleum migration are discussed, respectively. References | Related Articles | Metrics

Marine Oil Shale Depositional Environment of Qiangtang Basin in Northern Tibet FU Xiu-gen, WANG Jian, WANG Zheng-jiang, CHEN Wen-xi 2007, 28 (5):  529-533.  Abstract ( 125 )   PDF (263KB) ( 327 )   Save Two marine oil shale sections including Shenglihe and Biluocuo in Qiangtang basin, northern Tibet, are investigated in details. On the basis of isotope Sr variation, integrated with lithologic association, authigenic mineral assemblage, sedimentary structure and paleontologic evidence, the Shenglihe oil shale is classified into two major sedimentary environments such as tidal flat one and lagoon one. The intermittent occurrences of these two environmental deposits resulted in main forming condition of the Shenglihe oil shale, and so did the Biluocuo oil shale. The deposition of oil shale is not only associated with sea-level rise or fall and lagoon's intermittent opening, but also influenced by paleoclimate. The paleoclimate is the essential reason for formation and disappearance of the oil shale. Damp and hot climate is favorable for the formation of it, and droughty and scorching climate may restrict propagation of organisms, thus making a disappearance of it. References | Related Articles | Metrics

Forecast of Discovery Trend of Petroleum Resources in Jiyang Depression ZHOU Zong-ying 2007, 28 (5):  534-537.  Abstract ( 91 )   PDF (244KB) ( 209 )   Save In view of high level of petroleum Resources exploration in Jiyang depression, how much the resource potential has after all? How many reserves will be discovered in the future? It is the focus that the petroleum geologists pay more and more attention to. Based on changing trend of proved reserves and exploration benefit over the years in Jiyang depression, the life model simulation method (including Logistic, Hubbert, Compertz and HCZ models) and the exploration benefit method (including discovery rate per well and discovery rate per footage models) are applied to prediction of additional proved reserves accumulated in each period of 2006—2010, 2011—2015, 2016—2020 and 2021—2030, which provide scientific basis for drawing up the development plans in medium and long-term oil-gas exploration in this area. References | Related Articles | Metrics

The Expulsion Hydrocarbon Periods of Source Rock by Release of Over Pressure—An example of Qingshankou formation in Gulongsag FU Guang, WANG You-gong, SU Yu-ping 2007, 28 (5):  538-541.  Abstract ( 124 )   PDF (228KB) ( 267 )   Save By means of expulsion hydrocarbon mechanism of overpressure source rock, the method for release periods or times of overpressure is presented by interval transit time, obtaining that the overpressure of Qingshankou formation in Gulong sag in Songliao basin was ever released for three times. They are the end period of k1n, the middle-late period of k1n4 and the end period of k2m, and it is now in the fourth evolution process of overpressure. By comparison of these overpressure release periods with periods of oil threshold of k1qn source rock, the end period of k2m sedimentation is considered to be main expulsion hydrocarbon period of overpressure source rock of k1qn. This coincides with the periods of hydrocarbon accumulation in Saertu, Putaohua and Gaotaizi reservoirs in Daqing oilfield, indicating that the oil and gas expulsion from the overpressure source rock of Qingshankou formation were favorable to accumulate in large scale into these reservoirs. It is one of important conditions to form Daqing oilfield. References | Related Articles | Metrics

Modeling of 3D Permeability of Carbonate Reservoir in Lunnan Buried-Hill Oilfield, Tarim Basin WANG Zi-ming, SONG Wen-jie, LIN Shu-wen, LIU Ming-xin, HUANG Chuan, ZHANG Min, YUAN Jun 2007, 28 (5):  542-544.  Abstract ( 76 )   PDF (240KB) ( 162 )   Save Based on the fracture distribution and fractal pattern of carbonate reservoir in Lunnan buried-hill oilfield in Tarim basin, the 3D modeling for permeability variation function of this reservoir is established. The hardware and software data used for permeability modeling are processed, integrated with well log, well test interpretation and stress analysis results. The fractured reservoir permeability fractal prediction modeling technique is proposed. The numerical simulation and case study demonstrate that this technique is of good effect for application. References | Related Articles | Metrics

Geochemical Characteristics and Hydrocarbon Accumulation Mechanism of Mixed Oils in Subei Basin CHEN Qing-chun, CHANG Xiang-chun, GUO Hai-hua, PANG Ling-yun, SONG Zhen-xiang 2007, 28 (5):  545-548.  Abstract ( 98 )   PDF (247KB) ( 205 )   Save Oils in Jinhu sag are characterized by the typical immature-low mature, and some compounds with low thermal stability are identified. Carbon number preference index, odd-even predominance and hopane maturity show little difference of maturity between the oils. But the variation of sterane isomerisation parameter and source analysis indicates hat four migration and accumulation patterns with different maturities can be classified. Quantitative analysis shows that different percentage of immature oils is mixed with normal oils in Jinhu sag. The condensate associated with natural gas in Yancheng sag suggests both similarity and difference with lacustrine oils and marine oils. The light compositions of condensate are presented high mature, while the middle compositions assume immature to low mature and the heavy compositions show mature. The pattern of hydrocarbon accumulation with sources in lower strata and reservoirs in upper ones allows the mature oils to be scrubbed by the high mature gas, which appears the special feature of gas condensate. References | Related Articles | Metrics

Tertiary Tectonic Evolution and Its Relation with Biogas Accumulation in Qujing Basin HOU Yuguang 2007, 28 (5):  549-553.  Abstract ( 104 )   PDF (417KB) ( 225 )   Save The Paleogene-Neogene sedimentary basins in northeastern Yunnan province have good exploration prospects of biogenic gas, among which the representative one is Qujing basin. Through tectonic and sedimentary interpretations by 2D seismic lines, combining with geologic data and well logs, this paper discusses the tectonic/structural features and the basinal formation and evolution, and analyzes the relation between the tectonic/structural evolution and biogas accumulation. The study shows that during the fault-depression stage of Early-Middle Oligocene, the Caijiachong formation with mass lacustrine dark mudstone was deposited, which was as a major gas source rock. From Late Oligocene to Early Pliocene, as a result of cooling due to the entire uplift and erosion of this basin, the over-consumption of the organic matters in this formation was avoided, providing the organic materials for biogas accumulation since Quaternary. In the depression stage of Late Pliocene, the Ciying formation was deposited, which was the main period of forming its secondary coal-measure gas source rock, reservoir rock, cap rock and lithologic traps. In the end of Pliocene, the basin underwent the stage of compressionshearing uplift and shrinkage, characterized by the development of structural traps like fault-anticline and fault nose and structurallithologic traps. In the Quaternary, the basin was in steady subsidence stage, which was a period of biogas accumulation. The rate of biogas generation from gas source rocks, the vertical conductivity of faults, the preserving conditions of traps and their dynamic assemblages could be the key factors for controlling the late-stage biogas accumulation in this basin. References | Related Articles | Metrics

Relationship between Weather ing Crust Characteristics and Hydrocarbon Accumulation of Lower Permian in Malang Sag, Santanghu Basin LI Sen-ming, CHEN Feng-lai, QI Wan-zhen, HE Yan-qing, ZHAO Hao, SHI Lan-hua 2007, 28 (5):  554-556.  Abstract ( 119 )   PDF (228KB) ( 248 )   Save The weathering crust of Kalagang formation of Lower Permian in Malong sag, Santanghu basin is characterized by vertical weathered clay layer, highly weathered detritus, weakly weathered block layer and non-weathering rock interval. This paper analyzes the geologic conditions of the weathering crust formation and structural evolution feature, and then discusses the relationship between the weathering crust and the possible reservoir types. It is concluded that the favorable targets for petroleum exploration are in areas within denudation lines between the Tiaohu formation and Kalagang formation as well as area in east of denudation line of Kalagang formation. References | Related Articles | Metrics

Geochemical Characteristics of Hydrocarbons in Different States in Gasikula Oilfield, Qaidam Basin ZHAO Xin, SHI Ji-an, WANG Jin-peng, WANG Qi, WANG You-xiao 2007, 28 (5):  557-562.  Abstract ( 105 )   PDF (388KB) ( 220 )   Save Based on the stepwise separation and extraction on free oil, sealed oil, hydrocarbon in carbonate cement, bounded oil and inclusion hydrcarbon within quartz grain in six oil sand samples from Paleogene system and Neogene system in Gasikula oilfield of Qaidam basin, all these hydrocarbons are analyzed by GC-MS. The biomarkers of saturated hydrocarbon fractions in different states and their geochemical characteristics are studied. The result shows that the n-alkanes with single peak are dominant in the studied area with the range of carbon number from nC13 to nC42, ICP is lower than 1.2, being of weak odd-carbon preference. The ratio of m(Pr)/m(Ph) is lower than 0.39, being of phytane preference, assuming strong reducing environment. The high concentration of gammacerane indicates saline lacustrine depositional environment of source rocks. These differences of hydrocarbons in different states reflect the saline evolution process of lacustrine. Also, the relative high concentration of C27 regular steranes, hopanes and long-chain tricyclene from the oil sands suggest significant contributions of bacteria and algae to formation of hydrocarbons. The ratios of m (C29 sterane 20S)/m [C29 sterane (20S+ 20R)] and m(C29sterane ββ)/m(C29 sterane ββ+C29 sterane αα) suggest that the hydrocarbons in different states are crude oils generated from low mature and mature source rocks, and also reflect the different filling steps of sources into reservoirs. References | Related Articles | Metrics

The Main Controlling Factors of Deep Cracked Gas Accumulation in Dongying Sag YANG Xian-cheng, SUI Feng-gui, LI wen-tao, WANG Wen-lin, YU Lan, CHEN Xu-hui 2007, 28 (5):  563-565.  Abstract ( 95 )   PDF (200KB) ( 251 )   Save The deep cracked gas pool in Dongying sag is characterized by condensate gas reservoir and net gas reservoir. The gas source originates from high matured source rock of the lower sub-section of Es4. The factors controlling the cracked gas accumulation are studied by lab experiment, well log and seismic data analyses. Study shows that the hydrocarbon generation, hydrocarbon phase state and gas reservoir distribution are all controlled by in-situ geotemperature; the main reservoirs for the cracked gas accumulation are the mid-fan braided channel microfacies and front microfacies in nearshore submerged fan facies, and the reservoirs' conditions are improved by solution process, hence rising the gas-bearing property in them; the hydrocarbon migration and accumulation are controlled by the fluid potentials, allowing hydrocarbons to migrate from high potential zone in sag center to low potential zone at verges, finally to accumulate in the glutenites of favorable facies zones in faulted abrupt slope belt. It is concluded that the faulted abrupt slope belt in northern Dongying sag is an area for the deep cracked gas enrichment and distribution, thus it is also as a target for deep natural gas prospecting in the near future. References | Related Articles | Metrics

Exploration of K1q1 Non-Structural Reservoirs in Luxi Area of Junggar Basin YUE Yun-lei, YU Xing-he, LI Sheng-li, SHI Xin-pu, WANG Bin 2007, 28 (5):  566-568.  Abstract ( 99 )   PDF (216KB) ( 202 )   Save This paper anatomizes the known reservoirs based on the researches on the outcrops, core samples, drilling, well logs and 3D seismic data, etc., proposes for the first time that the reservoir in Wellblock Shinan-31 is lithological reservoir coming from water channel of gravity current and distinguishes the conglomerate of the bottom of Qingshuihe formation (K1q1) into basal conglomerate and slip glutenite. The two kinds of conglomerates have identified from cores, well logs and seismic profile in this area. Also, this paper takes an example to illustrate the recognition of non-structural reservoirs in terms of combination of geological thought with the techniques of sandcontent matching, 3D visualization and reservoir inversion. Finally, this paper generalizes the thoughts for exploration of non-structural reservoirs in this area by ways of fault ramp, terrace land and gravity current. References | Related Articles | Metrics

Reservoir Detection Based on Wavelet Packet Transform and Correlation Dimension WEN Xiao-tao, HE Zhen-hua, HUANG De-ji 2007, 28 (5):  569-571.  Abstract ( 85 )   PDF (206KB) ( 206 )   Save Oil, gas and water in a reservoir have different impedances, which may cause different reflection coefficients and waveforms. As a result, the value of correlation dimension is generally low. Seismic wave is the signal with definite bandwidth and the waveform is affected by all frequency components within the bandwidth, so the result could be unsatisfied if we calculate the correlation dimension directly. This paper proposes the method integrating wavelet packet with correlation dimension. Based on the feature that wavelet packet is suitable for decomposing high-low frequency component in detail, the high frequency component which can mirror details of seismic signals is extracted, and then the calculation of correlation dimension is made for the result given from frequency component processing. This method is applied to the middle oil layer of Triassic in Tahe area, and the calculated result is more satisfied. References | Related Articles | Metrics

Genetic Types of Sangonghe Sands and Assemblage Patterns of Mobei Arc in Junggar Basin ZHAO Jian-zhang, LI Shuang-wen, LIU Luo-fu, ZHANG You-ping 2007, 28 (5):  572-575.  Abstract ( 125 )   PDF (271KB) ( 202 )   Save The genetic types and association patterns of Jurassic Sangonghe sands are analyzed based on core, mud logging and well log data of all exploration wells and development wells in Mobei arc of Junggar basin. The types of sands include subaqueous distributary channel sand, mouth bar sand, distal bar sand, front sheet sand, bank bar sand of shallow-shore lacustrine. The subaqueous distributary channel sand is subdivided into truncated and completed ones. The association patterns are composed of superimposed subaqueous distributary channel sand, superimposed mouth bar sand, assemblage of subaqueous distributary channel-mouth bar sands, assemblage of distal bar-front sheet sands and superimposed bank bar sand. This paper analyzes the time-space distribution of these sand assemblages with different origins, and determines that these sand assemblages are controlled by sediment supplies and varied holding capacities. References | Related Articles | Metrics

Application of 2D Wavelet Transform to Prestack Separation of Surface Wave ZHANG Hua, PAN Dong-ming, ZHANG Xing-yan 2007, 28 (5):  576-578.  Abstract ( 101 )   PDF (230KB) ( 223 )   Save A new method for separation of prestack surface wave is proposed as follows: by apparent velocities of surface wave and effective wave, dividing the original seismic data into two areas with and without surface wave influence, and then making time-frequency analysis of area with the influence using 2D wavelet transform, from which picking up the effective wave, finally, making combination of it with the area without the influence. The result is the record after prestack separation of surface wave. This method is characterized by quick computation, good stability, desirable adaptability and no limitation. Real data processing shows that good result can be obtained by this method for prestack separation of surface wave. References | Related Articles | Metrics

Mechanism of CO2-Sandstone Interaction and Formative Authigenic Mineral Assemblage GAO Yu-qiao, LIU Li, QU Xi-yu 2007, 28 (5):  579-584.  Abstract ( 121 )   PDF (194KB) ( 302 )   Save When CO2 is injected into aquifer sandstone by natural or manual mode, diagenetic fluid will become weak acidic fluid, resulting in the decomposition of unstable minerals such as carbonate and feldspar and the precipitation of new minerals in host sandstone as well as the variation of sandstone porosity and permeability and formation water geochemical characteristics. Moreover, only a small amount of CO2 dissolves in water as a form of gas, while most of it is solidified in the host sandstone in forms of secondary minerals like calcite, dolomite and siderite, etc. The typical authigenic mineral assemblages include the dawsonite ±ferruginous carbonate ±other carbonate and the ankerite + kaolinite + authigenic quartz ones, in which the former is a typical authigenic mineral assemblage to trace CO2 migration and accumulation. This study on mechanism of CO2-sandstone interaction and formative authigenic mineral assemblage not only broadens the field of fluid-rock interaction in sedimentary basins, reveals the mass transportation between deep fluid and upper reservoir or between shallow source rock (or other rocks) and adjacent reservoir rocks, but also provides basic geologic information for the researches of sandstone reservoir quality evaluation, CO2 gas pool (or field) prediction and CO2 subsurface storage. References | Related Articles | Metrics

High Abundance Carotane from Marine Strata in Well Gulong-1 in Tarim Basin and Its Geological Significance GUO Jian-jun, CHEN Jian-fa, CHEN Zhong-yu 2007, 28 (5):  585-588.  Abstract ( 107 )   PDF (258KB) ( 301 )   Save β-carotane is a saturated C40 dicyclic alkane, which is generally used as an indicator of strongly reducing lacustrine environment. The organic matter detected from marine Ordovician strata in Well Gulong-1 in Tarim basin is characterized by high concentration of C28 sterane (28%~31%) and gammacerane (m(G)/m(C30H)=0.29~0.39), C23 concentration is predominant in tricyclic terpanes. These different features from source rocks of Middle-Upper Ordovician and Cambrian indicate that there is another source rock of Lower Ordovician or Cambian in southwestern slope of Manjiar sag or Guchengxu uplift formed in strongly reducing or oxygen-free sedimentary environment, besides existed Middle-Lower Cambian and Middle-Upper Ordovician source rocks, from which the hydrocarbon drainage had happened toward Guchengxu uplift. The geochemical analysis suggests that these organic maters underwent biodegradation here. References | Related Articles | Metrics

Controlling Factors of Premium Reservoir Rock in Tazhong Wellblock-82 LUO Chun-shu, YANG Hai-jun, CAI Zhen-zhong, WU Guang-hui, DONG Li-sheng 2007, 28 (5):  589-591.  Abstract ( 82 )   PDF (208KB) ( 297 )   Save Well Tazhong-82 is located in the middle segment of Tazhong No.1 slope break belt in Tarim basin, which is a one-thousandton well, a major breakthrough in low-energy zone inside the shelf-edged composite of reefs and banks of Upper Ordovician in 2005. But none of commercial oil-gas flow has been found from other 3 wells in west of Well Tachong-82. The analyses of core, thin section, well log data and seismic information indicate that corrosive caverns are developed in east and west sides of Well Tazhong-82, but the development of fracture differs from place to place. There exist very developed multistage structural fractures in east of Well Tazhong-82, which not only change the reservoir quality of reefs and banks, but also allow this reservoir permeability to be better, obtaining higher oilgas production. It suggests that it is fracture or secondary fault that controls the development of the reservoir rocks and hydrocarbon accumulation in this area. This paper can be as a guide for studying the reservoir rock and the well location in this area. References | Related Articles | Metrics

Pre-Drilling Quantitative Prediction of Sandstone Porosity of Middle-Upper Triassic Reservoir in Tuha Basin CHEN Xu, QI Wan-zhen, XING Dong-ling, XI Xiang-tao, XU Mei, SHI Lan-hua, DING Liang-tang 2007, 28 (5):  592-595.  Abstract ( 76 )   PDF (203KB) ( 206 )   Save The main controlling factor researches about sandstone porosity of Middle-Upper Triassic reservoir in Tuha oilfield indicate that thermal maturity is closely related to sandstone porosity, and its varied range is controlled by geothermal field and buried history. The thermal maturity is comprehensively reflected by time-temperature index. The index bigger than 115 means there exists the more dense sandstone of Middle-Upper Triassic reservoir. In three burial types of the sandstone, such as gradual type, slow-early and quick-late type and quick-early and rise-late type, the slow-early and quick-late type is the most favorable for the retention of the porosity. For the first and the second burial types, the time-temperature index of sandstone is well related to the buried depth of it, from which the effective depth of the Middle-Upper Triassic reservoir in Turpan depression can be calculated to average about 4 100 meters. Based on these correlations of time-temperature index vs porosity and time-temperature index vs burial depth, the preserved depth limit of sandstone porosity and the effective reservoir can be predicted before drilling. The case study shows that this method is feasible. References | Related Articles | Metrics

New Water flood Type-Curves to Predict Production Performance in Mid-Late Stage for Reservoir Development CHEN Jun, FENG Jie, WEN Tao 2007, 28 (5):  596-598.  Abstract ( 99 )   PDF (135KB) ( 179 )   Save In practices of oil fields by waterflooding process, a great number of equations of the type-curves have been put forward, among which A, B and C type-curves are widely adopted. However, all these curves would warp upward in mid-late stage of production, resulting in significant differences in recoverable reserves calculation. In this paper, a new set of type-curves are proposed for prediction of the production performance of such a stage, which can be applied to more accurate estimation of the reserves. The case study indicates that the results from the new type-curves are more accurate than those from conventional curves. References | Related Articles | Metrics

Permeability Prediction Method for Unconsolidated Heavy-Oil Reservoir during Cold Production SUN Jian-ping, TANG Yue-gang, FAN Zi-fei, LI Yun-juan 2007, 28 (5):  599-600.  Abstract ( 97 )   PDF (115KB) ( 355 )   Save Based on rock mechanical principles, integrated with the performance of heavy-oil cold production, the permeability changes of unconsolidated sandstone reservoirs with oil production rate and sand production rate are studied under the isothermal conditions. The quantitative permeability prediction model is developed for the heavy-oil cold production. This provides a basis for study of variation of oil production rate during cold production with sand control. References | Related Articles | Metrics

Calculation and Influencing Factors of Liquid Productivity Index in Low Permeability Reservoir ZHAO Jing, LIU Yi-kun, ZHAO Quna 2007, 28 (5):  601-603.  Abstract ( 188 )   PDF (161KB) ( 371 )   Save Based on the characteristics of low permeability oilfield such as poor petrophysical property, varied lithology, complicated porosity texture and serious heterogeneity, etc., the formula for calculation of liquid productivity index and oil productivity index are presented with either starting pressure or multi-force effects, and the effect of oil-water viscosity ratio and starting pressure gradient on changes of such indices with water cut in low permeability oilfield is analyzed. The results show that the effect of water cut on the indices is bigger. In the case of same water cut, the higher the oil-water viscosity, the bigger the ratio between starting pressure gradient and production pressure gradient as well as the dimensionless liquid productivity index. References | Related Articles | Metrics

Optimization of Injection Parameters for Alkali-Surfactant-Polymer Flooding—An example of Bei'erxi pilot area in Daqing oilfield YANG Cheng-lin, ZHOU Zheng-xiang, GUO Ming-li, WANG Sheng-li 2007, 28 (5):  604-606.  Abstract ( 85 )   PDF (177KB) ( 208 )   Save The chemical flooding model for reservoir of Bei'erxi pilot area in Daqing Saertu oilfield is developed, by which the influences of chemical concentration, slug size and injection rate to oil displacement efficiency with alkali-surfactant-polymer folding system containing main slug, auxiliary slug, pre-slug and over-slug are simulated, respectively. The results show that in the main slug the alkaline and surfactant concentrations have obvious effects on the oil recovery. And each of them has an optimal value relating to maximum recovery. Increasing polymer concentration of either alkali-surfactant-polymer main slug or auxiliary slug will significantly improve the incremental oil recovery. Change of sizes of these four slugs will result in change of EOR to a certain extent. References | Related Articles | Metrics

Calculation of Capillary Pressure Using Well Log Data WU Zeng-gui, WU Yong-bing, ZHANG Yi-tang 2007, 28 (5):  607-608.  Abstract ( 98 )   PDF (100KB) ( 280 )   Save In order to explain the abnormal water production behaviors of some oil wells in bottom water drive reservoir, a simple and practical method is introduced to obtain exponential model of capillary pressure from log interpretation data by statistics and regression. The relationship between capillary pressure and water saturation is established based on the assumption that the height of water rise in a single capillary is equivalent to the height of log samples above the bottom of oil-water transition zone. The method is useful when there is relative permeability data while capillary pressure test data are unavailable. The application of the model results in better match of water breakthrough time and water production performance. References | Related Articles | Metrics

Using Normal Probability Model to Forecast Performance of Water Cut in Water flood Oilfield SHEN Nan, DU Jun-she, WANG Guo-xian, FU Yu-fang, ZOU Min, QIAO Yue-hua, CAI Jun 2007, 28 (5):  609-611.  Abstract ( 81 )   PDF (207KB) ( 230 )   Save Using normal probability model is more simple and efficient to determine performance and characteristic parameter of waterflood oilfield, so it is feasible and practicable to forecast water cut and oil recovery of waterfood oilfield and evaluate its development measures. The comparison and application show that the normal probability model can be applied to forecasting the performance of water cut when the oilfield enters into medium water cut stage for either S-type, convex-type or concave-type curves. References | Related Articles | Metrics

Comparison and Analysis of Calculation of Different Reservoir Permeability Variation Factors LI Zi-jia, SONG Jie, QIAN Jie 2007, 28 (5):  612-614.  Abstract ( 254 )   PDF (101KB) ( 277 )   Save Permeability variation factor is a key parameter to describe reservoir heterogeneity. Field statistics includes the statistic theory equation and the empirical equation method proposed by Dykstra-Parsons in 1950, and each method has its own advantages and disadvantages as well as specific application scope. This paper presents the different variation factor statistic results for the east block of South District-1 in Daqing oilfield using the different methods. The study shows that comparison between the factors given by the same statistic method is a good way to ensure a correct result. References | Related Articles | Metrics

Application of Variable Rate Transient Testing to Ultra-Deep Horizontal Well WANG Tao, HAN Yi-long, WU Yi-ming, LEI Yu, LI Guang-yin, LUO Zhi-feng, LIU Lian, LI Ling 2007, 28 (5):  615-617.  Abstract ( 91 )   PDF (145KB) ( 236 )   Save Pressure transient testing is an important dynamic monitoring technique for obtaining reservoir information and strata parameters. The pressure build-up test and the pressure drawdown test to acquire the formation parameters are usually adopted in the oilfield. But the methods have to need certain closed-in time, which has a great influence to the production, especially to the high-yielding oil well and high-rate water injection well. Hence, a new technique of pressure transient testing is requested to overcome the disadvantage and acquire accurate information of the reservoir. The case study named variable rate transient testing in the ultra-deep horizontal well of the unsaturated sandstone reservoir of Tarim H field shows that the theory is correct, the application condition is specific, the field response is good, indicating that such a horizontal well test technique is a powerful support to the development scheme adjustment while keeping the high-yielding and the production stable in the oilfield. References | Related Articles | Metrics

A Systematic Classification of Water flood-Characteristic-Curve Methods LIU Ying, GAO Wen-jun 2007, 28 (5):  618-621.  Abstract ( 94 )   PDF (384KB) ( 260 )   Save As the most fundamental method for research of oilfield water cut, prediction of production index and calibration of recoverable reserves, the waterflood characteristic curve method comes to more than 70 types at home and abroad, among which some can be converted into others, and some can be simplified into another one by identical transforming and special parameter taking. This paper classifies the curves into a structure with five levels and nine types as well as corresponding inverse water cut and recovery percent diagram, which can be as a guide for the application (including programming), optimization, management and study of such characteristic curve methods in future. References | Related Articles | Metrics

Forecast of Hydrocarbon Reserves and Production Growth Trend in Junggar Basin DONG Wei-kai, JIN Tao, WANG Yu-tao, CAO Wei 2007, 28 (5):  622-624.  Abstract ( 139 )   PDF (200KB) ( 195 )   Save The varied trends, growth regulation of hydrocarbon reserves and productions as well as their degrees of proven Resources in different stages of exploration in some basins at home and abroad are presented, based on which the reserves, production growth regulation and varied trend of Xinjiang oilfields for over 50 years are analyzed, and the predictions of them in Junggar basin in coming one hundred years are made by Weng's method that determines cycle of life of the nonrenewable mineral Resources and selected HCZ model and Weibull model. It is concluded that the hydrocarbon reserves and productivity of Junggar basin are at the ascending stage, which coincides with the development patterns of the oilfield. References | Related Articles | Metrics

Reverse Analysis of Tectonic Stress Field and Its Application WANG Jin-long 2007, 28 (5):  625-627.  Abstract ( 78 )   PDF (176KB) ( 204 )   Save Based on measured stress data, integrating 2D finite element regression with fast lagrangian analysis of continua and multivariate regression, the tectonic tress field of studied area can be calculated. Taking a field block as an example, its tectonic stress regression analysis shows that the calculated results are in good agreement with the measured data and the conclusions from analyses of tectonic geology and petroleum geology. This method can be as reference to petroleum exploration and development. References | Related Articles | Metrics

Application of Imaging Logging Data to Stress Research of Anpeng Field SHEN Hui-lin, ZHU Yu-lin 2007, 28 (5):  628-630.  Abstract ( 99 )   PDF (162KB) ( 202 )   Save The size and orientation of stress are the important parameters in petroleum exploration and development. The imaging logging series such as dipole acoustic log and micro-resistivity scanning imaging log, etc. provides abundant basic data for the research of stress. This article selects the stress computation model fit for Anpeng field in accordance with the geologic feature and available well log and testing data, and then presents the method for computing each parameter required by the model using the imaging logging data. Moreover, the article proposes the method for determination of the stress orientation using the processing result of imaging logging data. Using these methods to research the stress of Anpeng field obtains good effectiveness which meets the needs of the field production. References | Related Articles | Metrics

A Method for Quick Interpretation of Parameters from Early Stage and Radial Flow Stage in Well Test Analysis ZOU Cun-you, LI Zhi-ping, AN Xiao-ping, LIU Guo-qing, HUANG Zhi-wen 2007, 28 (5):  631-634.  Abstract ( 106 )   PDF (242KB) ( 274 )   Save In the process of the software development of well test interpretation, a method for early-stage (pure wellbore storagy, fracture linear flow, fracture-formation dual linear flow) and radial flow stage parameters interpretation is proposed. Compared with conventional methods, the new method is of the advantages of quick, direct, precise and easy operation. Especially, the method can be used in conditions without data of mid-or early-stage, and still gaining satisfied interpretation results. References | Related Articles | Metrics

Investigation of Surface Layer Texture Using Surface Wave Information YAN Jun-hua, PENG Wen, ZHOU Xi-xiang 2007, 28 (5):  635-639.  Abstract ( 81 )   PDF (423KB) ( 260 )   Save Surface wave is separately used to explore the macro and micro structures of the earth in earthquake and engineering seismology. Surface wave, one of disturbing waves in petroleum exploration, carries also the information of surface layers in the earth. The low-velocity layer that concerned by petroleum prospecting belongs to the forward layer structure increasing from the top down. The forward model computation shows that the surface wave mainly exists in the range of base model. With p-ωtransform, the dispersion curves of petroleum seismic records can be effectively picked up. By dividing the surface layer structure into isopach thin layer and adopting smooth restriction, the basic dispersion curves can be inversed into the shear velocity of low-velocity layer, thus developing the structural model of surface layer. References | Related Articles | Metrics

A Feasible Method for Converted Wave Static Correction MA Zhao-jun, TANG Jian-ming, LIU Lian-sheng 2007, 28 (5):  644-646.  Abstract ( 86 )   PDF (326KB) ( 321 )   Save The thick and asymmetrical low-velocity belt of shear wave as well as low velocity of converted shear wave results in a great deal of converted wave static corrections and smart variations. This paper proposes a simple and feasible method for the converted wave static correction. The average velocity ratio of P-wave and S-wave is obtained by multi-component micro logging data. The converted wave long wavelength static correction is computed according to P-wave receiver statics and the ratio. The converted wave short wavelength static correction is gained by the difference between the fitted parabola time and the picked up reflection time through picking up clear reflection time on the dynamic correction shot gathers. The real data processing shows that this method can be used to solve the problem of converted wave static correction, and remarkably improve the quality of the converted wave records. The method has been applied to the 3D3C data processing in western Sichuan and good results have been obtained. References | Related Articles | Metrics

Types and Patterns of Hydrocarbon Accumulation of Stratigraphic Reservoirs YANG Yong, ZHA Ming, MENG Xian-long 2007, 28 (5):  647-649.  Abstract ( 125 )   PDF (148KB) ( 253 )   Save Stratigraphic reservoir is divided into four types such as stratigraphic unconformity system reservoir, stratigraphic unconformity barrier reservoir, stratigraphic onlap reservoir and biohermal reservoir. The unconformity has developed layered textures, which provide favorable conditions for hydrocarbon accumulation. Hydrocarbon reservoirs are all found in the upper and the lower of unconformable surface. Such a new type of reservoir is defined as the stratigraphic unconformity system reservoir which is characterized by hydrocarbon accumulation within the unconformity structural system. The stratigraphic unconformity barrier reservoir is dominated by truncated unconformity and folded one. The overlap belt tends to shaping complex stratigraphic reservoir. Therefore, stratigraphic reservoirs are all closely related to unconformity, and possess distinct patterns for hydrocarbon accumulation. The distribution of unconformity is of play propery. Different from conventional recognition regarding the unconformity as barrier-like planner system, unconformity could provide premium storage spaces. The unconformity hydrocarbon accumulation or reservoir is affected by several factors, but unconformity is of instructed effect on the hydrocarbon accumulation. References | Related Articles | Metrics

Approach to the Earth Origin and the Crustal Movement(1) HU Dao-xiong 2007, 28 (5):  650-653.  Abstract ( 126 )   PDF (111KB) ( 176 )   Save This paper discusses the origin and formation courses of the earth by beginning from material origin, and divided the earthforming stage into five periods such as polymerization, melting, crystallization, impact and expansion, shape, based on which proposes the original motivity of crustal movement, that is, expansion and compaction mechanism. By using the mechanism, the expressions of the earth and crustal movement such as continental drift, plate collision, ocean-floor spreading, magnetic inversion, non-asymmetric expansion and basinal subsidence, etc. are analyzed macroscopically. References | Related Articles | Metrics

Chemical Characteristics of Formation Water and Hydrocarbon Accumulation in Block C of Gobustan, Azerbaijan TANG Yong, ZHANG Shu-jun, PU Shi-zhao, LAN Wen-fang, DEN Yong, WANG Li 2007, 28 (5):  654-658.  Abstract ( 116 )   PDF (338KB) ( 201 )   Save There exist relatively individual formation water chemical systems in five petroliferous structures in Block C of Gobustan, Azerbaijan for reasons of differences in hydrocarbon accumulation and hydrogeologic conditions. The study shows that Solakhay structural reservoir of Bala VII formation is suggested to be a residual reservoir with a gas cap of crude biodegradation origin, according to its formation water chemical characteristic and petroleum geochemical feature. The chloride-calcium type water from Surakhany V-VII sand layers in West Duvanny structural reservoir reflects that it is a constant-volume gas reservoir with good seal conditions. The high-salinity water and chloride-calcium type water from Balakhany VII sand layer in Kyanizadag structural reservoir indicate that it is in good conservation condition. The sodium-bicarbonate type water from Balaknany VII sand layer in Dashgil structural reservoir is formed by crude biodegradation. And the sodium-sulfate type water found in Wellblock Das53 of the south side of Dashgil structural reservoir belongs to mixed genetic water possibly resulted from fluid accumulation and mixing in different periods. References | Related Articles | Metrics