Seismic characteristics of a reef carbonate reservoir and implications for hydrocarbon exploration in deepwater of the Qiongdongnan Basin, northern South China Sea

Our analysis of approximately 40,000 km of multichannel 2-D seismic data, reef oil-field seismic data, and data from several boreholes led to the identification of two areas of reef carbonate reservoirs in deepwater areas (water depth >= 500 in) of the Qiongdongnan Basin (QDNB), northern South China Sea. High-resolution sequence stratigraphic analysis revealed that the transgressive and highstand system tracts of the mid-Miocene Meishan Formation in the Beijiao and Ledong-Lingshui Depressions developed reef carbonates. The seismic features of the reef carbonates in these two areas include chaotic bedding, intermittent internal reflections, chaotic or blank reflections, mounded reflections, and apparent amplitude anomalies, similar to the seismic characteristics of the LH11-1 reef reservoir in the Dongsha Uplift and Island Reef of the Salawati Basin, Indonesia, which house large oil fields. The impedance values of reefs in the Beijiao and Ledong-Lingshui Depressions are 8000-9000 g/cc x m/s. Impedance sections reveal that the impedance of the LH11-1 reef reservoir in the northern South China Sea is 800010000 g/cc x m/s, whereas that of pure limestone in BD23-1-1 is > 10000 g/cc x m/s. The mid-Miocene paleogeography of the Beijiao Depression was dominated by offshore and neritic environments, with only part of the southern Beijiao uplift emergent at that time. The input of terrigenous sediments was relatively minor in this area, meaning that terrigenous source areas were insignificant in terms of the Beijiao Depression: reef carbonates were probably widely distributed throughout the depression, as with the Ledong-Lingshui Depression. The combined geological and geophysical data indicate that shelf margin atolls were well developed in the Beijiao Depression, as in the Ledong-Lingshui Depression where small-scale patch or pinnacle reefs developed. These reef carbonates are promising reservoirs, representing important targets for deepwater hydrocarbon exploration. (C) 2008 Elsevier Ltd. All rights reserved.

Gas hydrate associated with mud diapirs in southern Okinawa Trough

Many mud diapirs have been recognized in southern Okinawa Trough by a multi-channel seismic surveying on R/V KEXUE I in 2001. Gas hydrates have been identified, by the seismic reflection characteristics, the velocity analysis and the impedance inversion. Geothermal heat flow around the central of the mud diapir has been determined theoretically by the Bottom Simulating Reflectors (BSRs). Comparing the BSR derived and the measured heat flow values, we infer that the BSR immediately at the top of the mud diapirs indicate the base of the saturated gas hydrate formation zone (BSGHFZ), but not, as we ordinarily know, the base of the gas hydrate stability zone (BGHSZ), which could be explained by the abnormal regional background heat flow and free gas flux associated with mud diapirs. As a result, it helps us to better understand the generation mechanism of the gas hydrates associated with mud diapirs and to predict the gas hydrate potential in the southern Okinawa Trough. (C) 2008 Elsevier Ltd. All rights reserved.

Fine-grained Pleistocene deepwater turbidite channel system on the slope of Qiongdongnan Basin, northern South China Sea

Recently, as oil exploitation has become focused on deepwater slope areas. more multi-channel high resolution 2D and 3D seismic data were acquired in the deepwater part of the Qiongdongnan Basin, northern South China Sea. Based on 3D seismic data and coherence time slice, RMS and 3D visualization, a series of deepwater channels were recognized on the slope that probably developed in the late Quaternary period. These channels trend SW-NE to W-E and show bifurcations, levees, meander loops and avulsions. High Amplitude Reflections (HARs), typical for channel-levee complexes, are of only minor importance and were observed in one of the channel systems. Most of the detected channels are characterized by low-amplitude reflections, and so are different from the typical coarse-grained turbidite channels that had been discovered worldwide. The absence of well data in the study area made it difficult to determine the age and lithology of these channels. Using a neighboring drill hole and published data about such depositional systems worldwide, the lithology of these channels is likely to be dominated by mudstones with interbedded thin sandstones. These channels are formed by turbidity currents originated from the little scale mountain river of mid-Vietnam in SW direction and were probably accompanied by a relative sea level drop in the last glacial age. These channels discovered on the northern South China Sea slope are likely to be fine-grained, mud-dominant and low N:G deposits in a deepwater paleogeographic setting. (C) 2009 Elsevier Ltd. All rights reserved.

Gas hydrate occurrence on the continental slope of the northern South China Sea

High-resolution multi-channel seismic data and geological samples were collected during two research cruises of the R/V FENDOU 4 in 1999 and 2000. Studies on these data and samples together with results from sites 1143-1145 and 1148 of ODP Leg 184 suggest that the geological structure on the continental slope of the northern South China Sea is favorable for the formation of gas hydrates. Bottom simulating reflectors (BSRs) and geochemical anomalies which indicate the existence of gas hydrates have been recognized in sediments of the Xisha Trough, the Dongsha Rise and the accretionary wedge of the Manila subduction zone. These gas hydrates are generated by two different mechanisms depending on the tectonic regime and the seismic and geochemical characteristics. The first applies to the passive continental margin of the nor-them South China Sea on the Dongsha Rise and in the Xisha Trough. The gas hydrates are associated with diapiric structures, active faults, slumps and gravity flows as well as high Late Cenozoic sedimentation rates. Their seismic expression includes BSRs, seismic blanking zones and velocity anomalies. The second mechanism is operative on the active continental margin along the Manila subduction zone, especially in the accretionary wedge. Here, gas hydrate occurrence is marked by widespread BSRs and acoustic 'pull-down' possibly related to the existence of free gas in the sediments beneath the BSR. The thickness of the seismic blanking zones averages 250 m, suggesting that the stable gas hydrate zone has about the same thickness. (c) 2005 Elsevier Ltd. All rights reserved.

辽东湾隐蔽油气藏地球物理识别技术研究

In China and world, more than half the recent basin discovered reserves involve lithologic hydrocarbon reservoir reserves. The major target for further hydrocarbon basin exploration is the subtle reservoir. The Liaodong Bay prospect is much important in Bohai Sea, which includes Liaoxi low uplift, Liaodong uplift, Liaoxi sag and Liaozhong sag. After dozens years’ exploration in Liaodong Bay, few unexplored big-and-middle-sized favorable structural traps are remained and most of the stock structure targets are bad for fragmentary. Thus seeking for new prospect area and making a breakthrough, have become the unique way to relieve the severe exploration condition in Liaodong Bay. Technique Route Based on the petrophysical property of target area, the seismic forward inference of typical subtle trap model is expanded with analysis of logging, seismic and geologic data. According to petrophysical characteristics and forward inference and research on seismic response of actual seismic data in target area, the optimization of geophysical technique is used in subtle trap identification and the geophysical identification technique system of subtle reservoir is formed. The Key Research ① Petrophysical Model The petrophysical parameter is the basic parameter for seismic wave simulation. The seismic response difference of rocks bearing different fluids is required. With the crossplot of log data, the influence of petrophysical parameters on rock elastic properties of target area is analyzed, such as porosity, shale index, fluid property and saturation. Based on the current research on Biot-Gassmann and Kuster-Toksoz model, the petrophysical parameter calculator program which can be used for fluid substitution is established. ② S-wave evaluation based on conventional log data The shear velocity is needed during forward inference of AVO or other elastic wave field. But most of the recent conventional log data is lack of shear wave. Thus according to the research on petrophysical model, the rock S-wave parameter can be evaluated from conventional log data with probability inverse method. ③ AVO forward modeling based on well data For 6 wells in JZ31-6 block and 9 wells in LD22-1 block, the AVO forward modeling recording is made by log curve. The classification of AVO characteristics in objective interval is made by the lithologic information. ④ The 2D parameter model building and forward modeling of subtle hydrocarbon trap in target area. According to the formation interpretation of ESS03D seismic area, the 2D parameter model building and seismic wave field forward modeling are carried on the given and predicted subtle hydrocarbon trap with log curve. ⑤ The lithology and fluid identification of subtle trap in target area After study the seismic response characteristics of lithology and fluid in given target area, the optimization of geophysical technique is used for lithology identification and fluid forecast. ⑥The geophysical identification technique system of subtle reservoir The Innovative Points of this Paper ① Based on laboratory measurement and petrophysical model theory, the rock S-wave parameter can be evaluated from conventional log data with probability inverse method. Then the fluid substitution method based on B-G and K-T theory is provided. ② The method and workflow for simulating seismic wave field property of subtle hydrocarbon trap are established based on the petrophysical model building and forward modeling of wave equation. ③ The description of subtle trap structural feature is launched. According to the different reflection of frequency wave field structural attribute, the fluid property of subtle trap can be identified by wave field attenuation attribute and absorption analysis. ④ It’s the first time to identify subtle trap by geophysical technique and provide exploration drilling well location. ⑤ The technique system of subtle reservoir geophysical identification is formed to provide available workflow and research ideas for other region of interest.

准噶尔盆地西缘车排子地区隐蔽油气藏识别与勘探目标研究

After the half century exploration, previous scholar evaluating thought that there were poor Petro-Geological conditions in Chepaizi area of Zhungar basin. Recently, with the great discovery in the Well Pai2,the study on the subtle reservoir in Chepaizi area are gained great attentions by the scholars all over the world day by day. Chepaizi uplift is a inherited palaeohigh, and its structural traps are undeveloped. The sedimentary faces of Shawan Formation of Neogene have apron type of alluvial fan, alluvial plain, alluvial fan delta, salt lake, shore and shallow lake and so on. The sedimentary faces of Shawan Formation of Well Pai2 is alluvial fan delta and shore and shallow lake, the first part of Shawan Formation(N1s1) is the main target for exploration. Using the seismic forward, property analysis, spectral factorization, logging restrain inversion and so on, The spatial distribution of the sand reservoir and its hydrocarbon, predicted and 20 lithology traps in 5 substratums were carried out. The traps have a total areal of 107.13 Km2, and the geological reserves in it can reach 8703.7×104t. After comprehensive research on the trap,reservoir, cap and the condition of the hydrocarbon accumulation, it is considered that the elements of hydrocarbon in Chepaizi area are various. Because it can’t generate hydrocarbon, the oil and gas conducting and accumulation are the most important factors in this area, and the validity of the lithology traps in monoclinal is another important factor. Research indicates that the master control factor of the subtle reservoir in Chepaizi area is fault and sand. The sand of beach and sandbar provide the space for the hydrocarbon accumulation, the fault provides the migration channel for the hydrocarbon. Most faults have a characteristics of up seal and the down open, which not only can conduct hydrocarbon, but also can prevent hydrocarbon overtopping, therefore the effect trap is results of good match of fault and sand.

埕北断阶带油气运聚动力学研究

The problem of oil and gas migration and accumulation have been investigated for many years in petroleum geology field. However, it is still the most weak link. It is a challenge task to research the question about the dynamics of hydrocarbon migration and accumulation. The research area of this article,Chengbei step-fault zone is the important exploration area of Dagang oil field.The oil distribution is complicated in this area because of abundant faults and rock-reservoir-cap assemblage.In recent years, oil shows is often discovered, but no large-scale pool is found. The most important problem influencing exolore decision is lake of kowning about accumulation process of oil and resources potential. According to the geology characteristic and exolore difficult, the analysis principles of dynamics is used in this paper. The course from source to reservoir is considered as main research line, and relation of valid source rcok, migration dynamic and heterogeneous distribution of carrier is discussed especially in key time. By use of numerial model the couling of migration and passage is realized and dynamic process of oil migration is analysed quantitatively. On the basis of other research about structure and sendiment, basin model is built and parameters are choiced. The author has reconstructed characteristic and distribution of fluid dynamical in main pool-forming time by numerical model. The systems of oil migration and acuumulaiton are divided according to distribution of fluid potential. Furthermore, the scope of valid sourece rock and scale of discharging hydrocarbon is studied in geology history by the method of producting hydrocarbon poential. In carrier research, it is outstanding to analyse the function that fault controls the oil-gas migration and accumulation. According to the mechanism of fault sealing, the paper author puts forward a new quantitative method evaluating fault opening and sealing properties-fault connective probability by using the oil and gas shows in footwall and hangwall reservoir as the index of identifying fault sealing or non-sealing. In this method, many influencing factors are considered synthetically. Then the faut sealing propery of different position in third deimention of faults controlling hydrocarbon acummulation are quantitative evaluated, and it laies a foundation for building compex carrier systems. Ten models of carrier and dynamical are establishe by analysis of matching relation of all kinds of carriers in main pool-forming period. The forming process and distribution of main pathway has been studied quantitatively by Buoyancy-Percolation mode, which can conbine valid source rock, migration dynamical and carrier. On the basis of oil-gas migration and accumulation model, the author computes the loss of hydrocarbon in secondary migration, ahead of cap formation, and the quantity of valueless accumulation according to the stage of migration and accumulation and the losing mechamism. At the same time, resource potential is evaluated in every migration and accumulation system. It shows that the quanlity of middle systems arrive to 5.67×108t, which has a huge explore potential prospect. Finally, according to the result of quantitve analysis above mentioned, the favorable explore aims are forcasted by the way of overlapping migration pathway and valid trap and considering factors of pool-forming. The drilling of actual wells proved that the study result is credible. It would offer strong support to optimize explore project in Chengbei step-fault zone.

陕北何家集区延长组长4＋5－长6储层特征研究

Abstract： Hejiaji area lies on eastern part of Shanbei Slope in Ordos Basin and the primary oil-bearing bed is Chang 4＋5 and Chang 6 of Yanchang Formation. It is indicated that the sedimentary facies and reservoir characteristics restricted the hydrocarbon accumulation regularity by the geological information. Therefore, Applied with outcrop observation，core description, geophysical logging interpretation, thin section determination, Scanning Electron Microscope, reservoir lithology and physical property analysis and other analytic machinery, the sedimentary facies ,micro-characteristic and master control factors on hydrocarbon reservoir of Yanchang Formation in Hejiaji area are studied deeply by means of sedimentology，reservoir geology and petroleum geology and provide a reliably reference for later prospect . Delta facies are identified in Hejiaji area and of which distributary channels in delta plain microfacies controlled the distribution of sand bodies and accumulation of oil and gas.The distribution of sand bodies distributed from northeast to southwest are dominated by sedimentary facies . It was shown that the sandstones are medium to granule arkose，which the mud matrix is r and including，calcite，the content of matrix is lower and that mostly are cements which are mainly quartz and feldspar overgrowths and chlorite films, in the second place are hydromica and ferrocalcite. All the sandstones have entered a period of late diagenetic stage in which the dominant diagenesis types in the area are compaction, cementation and dissolution. Remnant intergranular porosity and feldspar dissolved pore are main pore types which are megalospore and medium pore. Medium-fine throat, fine throat and micro-fine throat are the mainly throat type. Pore texture can be classified as megalospore and fine throat type, medium-pore and micro-fine throat type mainly, and they are main accumulate interspace in research region. The reservoir of Yanchang Formation in Hejiaji area is low- pore and low- permeability in the mass which have strong heterogeneity in bed, interbedded and plane. Studying the parameter of pore and permeability comprehensively and consulting prevenient study results of evaluation of reservoir, the reservoir is classifiedⅡ，Ⅲ and Ⅳ three types in which the Ⅱand Ⅲ can be divided into Ⅱa and Ⅱb, Ⅲa and Ⅲb respectively. Ⅱb and Ⅲa are the main reservoir type in Hejiaji area which are about 72.73％and 80％percent of whole reservoir and effective reservoir respectively.

陕北桥镇油田延长组长2、长1油层组沉积相及储层研究

The Ordos Basin is a large-scale craton superimposed basin locating on the west of the North China platform, which was the hotspot of interior basin exploration and development. Qiaozhen oil field located in the Ganquan region of south-central of Ordos Basin. The paper is based on the existing research data, combined with the new theory and progress of the sedimentology, sequence stratigraphy, reservoir sedimentology, petroleum geology, etc, and analyzes systematically the sedimentary and reservoir characteristics in the chang2 and chang1 oil-bearing strata group of Yanchang formation On the basis of stratigraphic classification and comparison study, the strata chang2 and chang1 were divided into five intervals. Appling the method of cartography with single factor and dominance aspect, we have drawn contour line map of sand thickness, contour line map of ratio between sand thickness and stratum thickness. We discussed distribution characteristics of reservoir sand body and evolution of sedimentary facies and microfacies. And combining the field type section , lithologic characteristics, sedimentary structures, the sedimentary facies of single oil well and particle size analysis and according to the features of different sequence, the study area was divided into one sedimentary facies、three parfacies and ten microfacies. The author chew over the characteristics of every facies, parfacies and microfacies and spatial and temporal distribution. Comprehensive research on petrologic characteristics of reservoir , diagenesis types, pore types, distribution of sand bodies, physical properties, oiliness, reservoir heterogeneities, characteristics of interlayer, eventually research on synthetic classifying evaluation of reservoir.The reservoir is classified four types: Ⅰ、Ⅱ、Ⅲ、Ⅳ and pore type, fracture-porosity type. Take reservoir's average thickness, porosity, permeability, oil saturation and shale content as parameters, by using clustering analysis and discriminant analysis, the reservoir is classified three groups. Based on the evaluation, synthetizing the reservoir quality, the sealing ability of cap rock, trap types, reservoir-forming model ,in order to analyze the disciplinarian of accumulation oil&gas. Ultimately, many favorable zones were examined for chang23，chang223，chang222，chang221，chang212，chang12，chang11 intervals. There are twenty two favorable zones in the research area. Meanwhile deploy the next disposition scheme.

安塞油田三叠系延长组长10油层组沉积相研究

Ordos basin is a large-scale craton overlapping basin, which locates in western North China platform and possesses abundant hydrocarbon resources. Ansai area in 2007 to extend the head of Chang10 of Yangchang Formation has made breakthrough progress in the region, long a high of Gao52 was Chang10 industrial oil flow, for oil exploration Ansai Oil Field opened a new chapter. in 2008, high of Gao52, Wang519, Gao34 producing wells area of building and found the existence of Chang10 great potential for the discovery of Chang10 Reservoir, Ansai Oil Field for a new direction, showing a good exploration development prospects.The study of occurrence and distribution features of hydrocarbon should be made by new theories and evolutions of sedimentology, sequence stratigraphy, reservoir sedimentology and petroleum geology form different angles on the base of regional geology background. Ansai Oil Field is in mid Shanbei Slope, which is a considerable producing zone of Ordos basin. Chang10 of Yangchang Formation is an important oil-bearing series, which sedimentary formation was formed in Indosinian orogeny, Late Triassic, sedimentary background is a momentary uplifting in Ordos basin, and exploration and exploitation of hydrocarbon in this area is very important. To further descripte disciplinarian of accumulation hydrocarbon, carefully study on sedimentary facies, reservoir type and disciplinarian of accumulation hydrocarbon of Chang10 of Yangchang Formation in study area is needed. By collecting date of field profile, outcrop, core and many other geological, through sedimentary and oil geological analysis, sedimentary facies types were identified, distributing of sedimentary facies and extension of sand body were analyzed too. Finally, the main controlling factors of hydrocarbon and the favorable areas were found out by deeply studying sedimentary system and disciplinarian of accumulation oil&gas in Chang10 of Yangchang Formation, Late Triassic in Ansai Oil Field. Chang10 of Yangchang Formation is main study formation, which is divided into three members (Chang101, Chang102 and Chang103), Chang101 is subdivided into three (Chang1011, Chang1012and Chang1013) reservoirs. By defining Layered borderline between every member and detailed describing rock and electro characteristic, member zonation become more reasonable and accurate also sedimentary facies and disciplinarian of accumulation oil&gas in study area are confirmed Through researching sedimentary facies, reservoir sand and hydrocarbon migration, accumulation, distribution, hydrocarbon accumulation models of Chang10 of Yangchang Formation in study area is pointed out, which is lithologic hydrocarbon reservoir and tectonic-lithologic hydrocarbon reservoir. Different play is formed by different processes and factors. Through analysis of reservoir property, trap type and accumulation model, several favorable exploration areas can be found out in Chang 10 reservoirs （Chang1011, Chang1012and Chang1013） of the Ansai Oil Field.

流体地球化学：成因、流动和流体-岩石相互作用及塔里木盆地实例研究

Geofluid in sedimentary basins is related to petroleum generation, migration, accumulation and preservation, and is a topic of geological frontier. By integrating the multi-discipline methods of petroleum geochemistry, sedimentology, hydrogeology, petroleum geology and experimental geochemistry, the thesis has carried out experiments of microcline dissolution in solutions with organic acids, crude oil, brines with high total dissolved solids (TDS), and has dealt with Al distribution between the crude oil and the brines after the experiments. Cases for study includes Central Tarim, Hetianhe Gas Field and Kucha forland basin with data containing fluid chemistry and isotopic compositions, thin sections of sandstones and carbonates, homogenization temperatures and salinities of fluid inclusions, isotopic compositions of bulk rock and autigenic minerals. The aims are to elucidate fluid origin and flow in the three areas, effect of hydrocarbon emplacement on diagenesis, and to show occurrence of microbe-mediated, and thermochemical sulfate reduction in the Tarim Basin. Microcline dissolution experiments show that after 100 hour, part of the dissolved Al distributes in the crude oil, and the Al concentrations in the crude oil rise when organic acids are added. The result can be used to explain that most oilfield waters in the Tarim Basin are characterized by less than 3mg/L Al. Crude oil added to the solutions can enhance microcline dissolution, which is also observed in the case - Silurian sandstones with early crude oil emplacement in the Central Tarim. Al and Si have higher concentrations in the experiments of oxalic acid than of acetic acid under the same pH conditions, suggesting that there exist Al-oxalate and Si-oxalate complexes. Presence of acetate can enhance the activity of Ca and Al, but Al concentrations have not been increased significantly due to formation of small Al-acetate complex during the experiments. Relationships between δD and δ~(18)O in conjunction with chemistry of oilfield waters show that the waters are evaporated connate waters, which subsequently mixed with meteoric water, and were influenced by water-rock interactions such as salt dissolution, dolomitization of calcite, albitization of feldspar. In the Hetianhe Gas Field where salt dissolution took place, δD and δ~(18)O values can be used to trace nicely meteoric water recharge area and flow direction, but TDS can not. Part of the waters have high TDS but very light δD and δ~(18)O. When combined with paleo-topography, or fluid potentials, meteoric water is suggested to flow eastward in the Hetianhe Gas Field, which is the same with the Central Tarim. Whist in the Kuche forland basin, meteoric water may have permeated Cambrian-Ordovician strata. Relationship between ~(87)Sr/~(86)Sr and 1/Sr can be used to indicate migration and mixing of brines from carbonate strata (low ~(87)Sr/~(86)Sr ratio but high Sr content), clastic strata (high ~(87)Sr/~(86)Sr ratio but low Sr content) and crystalline basement (high ~(87)Sr/~(86)Sr ratio and heavy δ~(18)O value). Using this approach, it can be found that ~(87)Sr-depleted brine from Ordovician carbonates have migrated up to and mixed with ~(87)Sr-enriched waters from Silurian and Carboniferous sandstones, and that Silurian brines have mixed with meteoric water. In the Kuche forland basin, brines from the Cambrian and Ordovician carbonates have higher ~(87)Sr/~(86)Sr ratios than those from the overlying sandstones, when combined with chemistry, δ~(15)N and ~3He/~4He ratios of the coexisting natural gases, suggesting that the brines were derived from the basement. There exists some debate on the effect of hydrocarbon emplacement on mineral diagenesis. Case-study from Silurian sandstones in the Central Tarim show that quartz has kept overgrowing secondarily when oil saturation was decreased by meteoric water flushing subsequently to hydrocarbon emplacement. Silicon precipitates on the water-wet quartz surface, leading to decreased Si concentration close to the surface. A Si grads can result in Si diffusion, which supplies Si for quartz overgrowth. Hydrocarbon oxidation-sulfate reduction is an important type of organic-inorganic interaction. Not only can it make secondary alteration of hydrocarbons, but generate H_2S and CO_2 gases which can improve reservoir property. Thermochemical sulfate reduction took place at the temperatures more than 125 ℃ to 140 ℃ in the Cambrian-Ordovician carbonates, the products - H_2S and CO_2 gases migrated up to the Silurian, and precipitated as pyrite and calcite, respectively. The pyrite has an average δ~(34)S value close to those of Ordovician seawater and anhydrite, and calcite has δ~(13)C value as low as -21.5‰. In the Hetianhe Gas Field, sulfate reduction bacteria carried by meteoric water flowing eastward may have preferentially depleted ~(12)C of light hydrocarbon gases, and results in heavier δ~(13)C values of the residual hydrocarbon gases and higher molar CO_2 in the natural gases in the west than in the east. Coexisting pyrite has δ~(34)S values as low as -24.9‰.

油气运聚动力学的模拟分析——以准噶尔盆地为例

The petroleum migration, happening in the geologic past, is the very important and complex dynamic processes in the petroleum systems. It plays a linking role among all static factors in a system. The accumulation is in fact the result of the petroleum migration. For the petroleum geology, the dynamics research of the petroleum migration refers to the mechanism and process research, as well as the use of the quantitative methods. In this thesis, combining with the qualitative analysis and quantitative modeling, the author manages to discuss theoretically some key problems dealing with migration processes, which have not been solved yet, and to apply the studied results in petroleum system analysis in actual basins. The basin analysis offers the base of the numerical modeling for geological phenomena occurring in sedimentary basins, that consists of the sedimentary facies analysis, the section reconstructing technique, eroded thickness estimating, etc. The methods to construct the geologic model, which is needed in the research of oil and gas migration and accumulation, are discussed. The basin analysis offers also the possibility for the latter modeling works to get and select the parameters, such as stratum's thickness, age, stratigraphy etc. Modeling works were done by using two basin modeling softwares: Basin_Mod and TPC_Mod. The role of compaction during the secondary migration and the heterogeneity of migrating paths within the clastic carrier are modeled. And the conclusions were applied in the migration studies in the Jungaer Basin, lying on the Northwest part of the China. To construct a reliable migration model, the author studied the characteristics of the sedimentation, the pore fluid pressure evolution, as well as the distribution and the evolution of fluid potential, following the tectonic evolution of the Jungaer Basin. The geochemical prospecting results were used to evidence and to calibrate the migration processes: the oil-source correlation, the distribution of the properties of oil, gas and water. Finally, two important petroleum systems, Permian one and Jurassic one were studied and identified, according, principally, to the studies on the petroleum migration within the Jungaer Basin. Since the oil, as well as the gas, moves mainly in separate phase during the secondary migration, their migrating behaviors would be determined by the dynamics conditions of migration, including the driving forces and pathways. Based on such a consideration, the further understandings may be acquired: the roles played by permeable carriers and low-permeable source rock would be very different in compaction, overpressure generation, petroleum migration, and so on. With the numerical method, the effect of the compaction on the secondary migration was analyzed and the results show that the pressure gradient and the flux resulted from compaction are so small that could be neglected by comparing to the buoyancy of oil. The main secondary migration driving forces are therefore buoyancy and capillary within a hydrostatic system. Modeling with the commercial software-Basin_Mod, the migration pathways of petroleum in clastic carriers seem to be inhomogeneous, controlled by heterogeneity of the driving force, which in turn resulted from the topography of seals, the fabrics and the capillary pressure of the clastic carriers. Furthermore, the direct and indirect methods to study fault-sealing properties in the course of migration were systemically summarized. They may be characterized directly by lithological juxtaposition, clay smear and diagenesis, and indirectly the comparing the pressures and fluid properties in the walls at two apartments of a fault. In Jungaer Basin, the abnormal pressures are found in the formations beneath Badaowan or Baijantan Formation. The occurrence of the overpressure seems controlled by the stratigraphy. The rapid sedimentation, tectonic pressuring, clay sealing, chemical diagensis were considered as the principal pressuring mechanisms. The evolution of fluid pressure is influenced differently at different parts of the basin by the tectonic stresses. So the basin appears different pressure evolution cycles from each part to another during the geological history. By coupling the results of thermal evolution, pressure evolution and organic matter maturation, the area and the period of primary migration were acquired and used to determine the secondary migration time and range. The primary migration in Fengcheng Formation happened from latter Triassic to early Jurassic in the main depressions. The main period of lower-Wuerhe Formation was at latter Jurassic in Changji, Shawan and Pen-1-jing-xi Depression, and at the end of early Cretaceous in Mahu Depression. The primary migration in Badaowan and Sangonghe Formation is at the end of early-Cretaceous in Changji Depression. After then, the fluid potential of oil is calculated at the key time determined from area and time of the primary migration. Generally, fluid potential of oil is high in the depressions and low at the uplifts. Synthetically, it is recognized that the petroleum migration in the Jungaer Basin is very complex, that leads us to classify the evolution of petroleum systems in Northwestern China as a primary stage and a reformed one. The remigration of accumulated petroleum, caused by the reformation of the basin, results in the generation of multiple petroleum systems. The faults and unconformities are usually the linkers among the original petroleum systems. The Permian petroleum system in Jungaer Basin is such a multiple petroleum system. However, the Jurassic petroleum system stays still in its primary stage, thought the strong influences of the new tectonic activities.

砂砾岩储层流动单元四维模型研究

This article is an important part of "95" technological subject of SINOPEC. It has a large number of difficulties and workloads, and has significant theoretical meanings and practical value. The study area is composed of sandstone & conglomerate reservoir of alluvial fan & fan delta, which belong to Sha3 lower member and Sha4 upper member of lower tertiary of Yong'an Town Oilfield in Dongying Depression. The target stataum develops in the hanging wall of the synsedimentary fault in the scarp zone of Dongying Depression. The frequently intense movements result in the variation of sandstone and conglomerate reservoir and the evolution of the time and space of Sha3 lower member and Sha4 upper member in Yong'an Town Oilfield. As a result, it is difficult for the individual reservoir correlation at the root of fan, which bring about a tackle problem for the exploitation of oilfield. In this background, the research of fluid units will be more difficult. In this article, the new concepts, the new methods, and the new techniques of sedimentology, petroleum geology, reservoir geology, physics of crystal surface, dynamic & static state reservoir description and well logging geology are synthetically applied, and the computer technology are made full uses of, and the identifying, dividing and appraising of the two-formation-type sandstone & conglomerate reservoir fluid units of Sha3 lower member and Sha4 upper member systemically analyzed in Yong'an Town Oilfield, Dongying Depression. For the first time, the single-well model, the section model, the plane model, the nuclear magnetism log model, the microcosmic network model, the 4-D geology model and the simulation model of the two-formation-type reservoir fluid units of the of sandstone & conglomerate reservoir of Sha3 lower member and Sha4 upper member are established, and the formative mechanism and distributing & enrichment laws of oil-gas of the two type of sandstone and conglomerate reservoir fluid units are revealed. This article established the optimizing, identifying, classifying and appraising standard of the two-formation-type reservoir fluid units of the of sandstone and conglomerate reservoir of Sha3 lower member and Sha4 upper member, which settles the substantial foundations for static state model of the fluid units, reveals the macroscopic & microcosmic various laws of geometrical static state of the fluid units, and instructs the oil exploitation. This article established static state model of the two-formation-type sandstone and conglomerate reservoir fluid units by using the multi-subject theories, information and techniques, and reveals the geometrical configuration, special distribution and the oil-gas enrichment laws of the sandstone and conglomerate reservoir fluid units. For the first time, we established the nuclear magnetism log model of the two-formation-type sandstone and conglomerate reservoir of Sha3 lower member and Sha4 upper member, which reveals not only the character and distributing laws of the porosity and permeability, bat also the formation and distribution of the movable fluid. It established six type of microcosmic net model of the two-formation-type sandstone and conglomerate reservoir of Sha3 lower member and Sha4 upper member in the working area by using the advanced theories, such as rock thin section, SEM, image analysis, intrusive mercury, mold, rock C.T. measure & test image etc., which reveals the microcosmic characteristic of porosity & throat, filterate mode and microcosmic oil-gas enrichment laws of the sandstone and conglomerate reservoir. For the first time, it sets up the 4-D model and mathematic model of the sandstone and conglomerate reservoir, which reveals the distributing and evolving laws of macroscopic & microcosmic parameters of the two-formation-type sandstone and conglomerate reservoir and oil-gas in 4-D space. At the same time, it also forecasts the oil-gas distribution and instructs the oilfield exploitation. It established reservoir simulation model, which reveals the filterate character and distributing laws of oil-gas in different porosity & throat net models. This article established the assistant theories and techniques for researching, describing, indicating and forecasting the sandstone and conglomerate reservoir fluid units, and develops the theories and techniques of the land faces faulted basin exploitation geology. In instructing oilfield exploitation, it had won the notable economic & social benefits.