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.

Mesozoic-Cenozoic tectonic evolution of the Zhuanghai area, Bohai-Bay Basin, east China: the application of balanced cross-sections

The technique of balancing cross-sections, an important method for studying the tectonic history of sedimentary basins, has many applications. It enables one to compile charts for petroleum exploration and development, and growth sections of ancient structures can be restored so that the structural growth history can be studied. In order to study tectonic evolution in the Zhuanghai area of the Bohai-Bay basin, we selected two seismic profiles and compiled two structural growth sections. Based on the two balanced cross-sections, the evolution can be divided into four phases: the Triassic-Middle Jurassic phase, Late Jurassic - Cretaceous phase, Palaeogene extension phase, and Late Palaeogene-to-present phase. The whole area was uplifted during the Triassic-Middle Jurassic phase because of intense extrusion stress related to the Indo-China movement. During the Late Jurassic and Early Cretaceous, intense extension occurred in east China, and the whole area rifted, leading to the deposition of a thick sedimentary sequence. In the Late Cretaceous, the area suffered uplift and compression associated with the sinistral strike slip of the Tanlu fault. In the Palaeogene, a rifting basin developed in the area. Finally, it became stable and was placed in its present position by dextral strike-slip motion. In addition, some problems associated with compiling balanced cross-sections are discussed.

东海沿岸贝类体内石油烃和有机氯农药的分布特征及评价

本研究分别于2006、2007年5月在东海沿岸海域22个站位采集牡蛎、贻贝、四角蛤蜊、文蛤、花蛤5种贝类样品，采用荧光分光光度法和气相色谱法检测贝类体内的石油烃（TPHs）和有机氯农药(HCHs和DDTs) 含量，分析东海沿岸海域贝类体内的TPHs、HCHs和DDTs的时空分布特征和HCHs、DDTs的组分特征，比较不同贝类体内污染物含量的差异，探讨HCHs和DDTs的来源，并对贝类进行初步海洋生物质量评价和人体健康风险评价。研究结果表明： （1）东海沿岸海域贝类体内TPHs含量范围为0.40 74.40 mg kg-1，平均含量为9.42 mg kg-1；HCHs含量为ND～5.42×10-3mg kg-1，平均含量为1.47×10-3 mg kg-1；DDTs含量为2.09×10-3～197.66×10-3mg kg-1，平均含量为38.05×10-3 mg kg-1。其中，TPHs含量在长江口及邻近海域较高， HCHs和DDTs含量在江苏省的如东、海门和浙江省的各海域含量较高。与2006年相比，2007年贝类体内TPHs含量与2006年基本持平，HCHs含量有稍微降低，但是DDTs含量有明显升高趋势。 （2）HCHs和DDTs组分分析表明，α-HCH和β-HCH占HCHs总量的绝大多数，γ-HCH和δ-HCH仅有极少量检出，大多数区域的α-HCH/γ-HCH比值在4-7之间，说明研究区域内有新的HCHs污染源； DDTs 中O,P’-DDT/P,P'-DDT的比值远高于工业DDTs中O,P’-DDT/P,P'-DDT的比值，分析认为其与周围区域使用三氯杀螨醇密切有关。 （3）贝类体内的TPHs、HCHs和DDTs与水体、沉积物中的相应有机物存在正相关性。相对于TPHs和HCHs，DDTs更容易在贝类体内富集；牡蛎对TPHs和HCHs、DDTs的累积能力明显高于四角蛤蜊和贻贝。 （4）质量评价显示TPHs在局部海域超标，HCHs未超标，DDTs含量超标严重。人体健康风险评估结果显示，东海沿岸海域贝类体内HCHs和DDTs的致癌风险和暴露风险均在可接受的范围之内，消费者因食用监测海域的贝类而受到HCHs和DDTs危害的可能性不大。 （5）与世界其他海域比较表明，东海海域贝类TPHs和HCHs含量处于中等水平， DDTs含量处于比较高的水平。

Sources and distribution of aliphatic and polyaromatic hydrocarbons in sediments of Jiaozhou Bay, Qingdao, China

The composition and distribution of aliphatic (n-alkanes) and polyaromatic hydrocarbons (PAHs) were measured for the surface sediments collected at 25 sites from Jiaozhou Bay, Qingdao, China. Total n-alkanes and PAH concentrations ranged from 0.5 to 8.2 mu g/gdw and 0.02 to 2.2 mu g/gdw, respectively, and the distribution of both n-alkanes and PAHs showed large spatial variations in the bay. The distribution of PAHs in the sediments was predominated by the three or more ring compounds. High hydrocarbon levels were generally found in the areas associated with high anthropogenic impact and port activities in the bay. The calculated hydrocarbon indexes suggest that petroleum contamination was the main source of n-alkanes, while both pyrolytic and petrogenic sources contributed PAHs to the surface sediments of Jiaozhou Bay. In comparison to other polluted coastal sediments, the level of contamination from both aliphatic hydrocarbons and PAHs in Jiaozhou Bay sediments is relatively low at the present time. (c) 2005 Elsevier Ltd. All rights reserved.

Prediction of marine sediment corrosion by fuzzy clustering analysis

Along with the development of marine industries, especially marine petroleum exploitation, more and more pipelines are buried in the marine sediment. It is necessary and useful to know the corrosion environment and corrosiveness of marine sediment. In this paper, field corrosion environmental factors were investigated in Liaodong Bay marine sediment containing sulfate-reducing bacteria (SRB) and corrosion rate of steel in the partly sediment specimens were determined by the transplanting burying method. Based on the data, the fuzzy clustering analysis (FCA) was applied to evaluate and predict the corrosiveness of marine sediment. On that basis, the influence factors of corrosion damage were discussed.

碳酸盐岩缝洞型储层地球物理响应特征及预测方法研究

Proven by the petroleum exploration activities, the karsts-fissure reservoir in carbonate rocks is significant to find out the large scale oil & gas field. They are made up of the four reservoir types: karsts-cave, karsts-crack, crack-cave and fracture-pore-cave. Each reservoir space and each reservoir bed has different features of reservoir heterogeneity and small scale of pore-crack-cave. The fracture-cave reservoir in carbonate rocks is characteristic by multi-types and long oiliness well. The reservoir shape is controlled by the irregular pore-crack-cave. The development level of fracture and karst-cave is the key element of hydrocarbon enriching, high productivity and stable production. However, most of Carbonate formation are buried deeply and the signal-ration-noise of seismic reflection are very low. It is reason why the fracture-cave reservoir are difficult to be predicted effectively. In terms of surveyed and studied lots of the former research outcome, The author applied the methods of synthetical reservoir geophysical prediction from two ways including macrosopic and microcomic technics in terms of the reservoir-cap condition, geophysics and geology feature and difficulty of prediction in carbonate rocks. It is guiden by the new ideas of stratigraphy, sedimentology, sedimentography, reservoir geology and karst geology. The geophysics technology is key technics. In aspects of macroscopic studies, starting off the three efficiencies of controlling the reservoir distribution including sedimental facies, karst and fracture, by means of comprehensive utilization of geology, geophysics, boring well and well log, the study of reservoir features and karst inside story are developed in terms of data of individual well and multiple well. Through establishing the carbonate deposition model, karstic model and fracture model, the macro-distribution laws of carbonatite are carried out by the study of coherence analysis, seismic reflection feature analysis and palaeotectonics analysis. In aspects of microcosmic studies, starting off analysis in reservoir geophysical response feature of fracture and karst-cave model according to guidance of the macroscopic geological model in carbonate reservoir, the methods of the carbonate reservoir prediction are developed by comprehensively utilization of seismic multi-attribution intersection analysis, seismic inversion restricted by log, seismic discontinuity analysis, seimic spectrum attenuation gradient, moniliform reflection feature analysis and multiparameter karst reservoir appraisement.Through application of carbonate reservoir synthetical geophysics prediction, the author r successfully develops the beneficial reservoir distribution province in Ordovician of Katake block 1in middle Tarim basin. The fracture-cave reservoir distributions are delineated. The prospect direction and favorable aims are demonstrated. There are a set of carbonate reservoir prediction methods in middle Tarim basin. It is the favorable basic technique in predicting reservoir of the Ordovician carbonate in middle Tarim. Proven by exploration drilling, the favorable region of moniliform reflection fracture and pore-cave and cave-fracture in lower-middle Ordovician are coincidence with the region of hydrocarbon show. It’s indicated that the reservoir prediction methods described in the study of Ordovician carbonate formation are feasible practicably.

全信息精细储层预测方法研究与实践-以周清庄油田沙三段油藏为例

With the continuously proceeding of petroleum exploratory development in China, exploratory development becomes more and more difficult. For increasing reserve volume and production, lithologic hydrocarbon reservoir has been the most workable, potential and universality exploration targets. In the past, Dagang Oil Field use the complicated fault reservoir theory as the guide, develop and form a suit of matching construction and instrument in prospecting complicated fault reservoir that reach top of exploration industry in China. But the research of lithologic hydrocarbon reservoir is not much, which affects the exploitation progress of lithologic hydrocarbon reservoir. In this thesis, is object, through the depth study of lithologic deposition in Shasan segment of Zhouqingzhuang Oil Field, a suit of holographic fine reservoir bed forecasting techniques is built up and finally gets following main results: 1. Applying geology, seism, drilling, logging and other information to sensitivity preferences, geological model, inversion and integrated stratum evaluation, realizing the method and flow of refined multi-information stratum forecast. 2. Built up a full three dimensional fine structural interpretation method: in view of r problem of accurately demarcating 90% inclined well, propose a inclined well air space demarcating method, make bed demarcating more exactly; in view of problem of faults demarcating and combination in seismic interpretation, propose a computational method of seismic interference based on wavelet translation, make identify the fault in different level more dependable and reasonable; for exactly identifying structural attitude, propose a velocity modeling method under multi-well restriction, make structural attitude closer to the facts. 3. Built up a high accuracy reservoir bed inversion method: in view of problem in exactly identifying reservoir and nonreservoir with conventional wave impedance inversion method in this place, propose a reservoir log response characteristic analysis and sensible log parameter inversion method. ①analysis log response of reservoir and nonreservoir in region of interest, make definite the most sensible log parameter in identifying reservoir and nonreservoir in this region; ②make sensible log parameter inversion based on wave impedance inversion, to improve inversion accuracy, the thickness of recognizable reservoir bed reach 4-5m. 4. Built up a 4-D reservoir forcasting circuit: in view of difficulty that in lithologic hydrocarbon reservoir making reservoir space characteristic clear by using structural map and reservoir forecasting techniques once only, propose a 4-D reservoir forcasting circuit. In other words, based on development conceptual design, forcast reservoir of different time, namely multiple 3D reservoir forcasting in time queue, each time the accuracy degree of reservoir forcasting is improved since apply the new well material, thereby achieve high quality and highly efficient in exploratory development. During exploratory development lithologic depositin in Shasan segment of Zhouqingzhuang Oil Field, there are thirteen wells get 100% success rate, which sufficiently proves that this suit of method is scientific and effective.

四川盆地构造控藏规律研究

Firstly, established sequence stratigraphy of Sinian System-Middle Triassic Series framework in Sichuan basin,be divided into 21 second-level sequence stratigraphy and 105 third-level sequence stratigraphy.From many aspects,discussed sequence stratigraphy characteristic. On the foundation of structure unconformity and fission track analysis, on the ground of An county-Shuinin county regional seismic section, using the positive evolution equilibrium principle technology, comprehensivly be mapped structure evolution of Sichuan basin. It can be divided into seven stages, that is :Pre-Sinian basement stage, cratonic depression basin(Z1-S)stage, cratonic rifted basin(D-T2)stage, passive continental margin(T3x1-3)stage, foreland basin(T3x4-6)stage, depression basin (Jurassic Period-Miocene Epoch) stage, formed basin (Holocene Epoch) stage. Analysis on structure evolution history,burial history,source rocks thermal evolution history, Maoba changxing formation gas pool forming process can be classified into four stages: ancient lithological oil pool stages in Indosinian-early Yanshanian period（T-J1-2）, ancient structure- lithological gas pool stages in middle Yanshanian period（J3-K1）, structure- lithological gas pool setting stages in last Yanshanian period（K2）, structure- lithological gas pool adjusting and transformation stages in Himalayan period（R-Q）. Maoba feixianguan formation gas pool forming process can be classified into two stages: second structure gas pool stages in last Yanshanian period（K2）,second structure gas pool physical adjusting and transformation stages in Himalayan period（R-Q）,and summarize reservoir formation model. On the base of newest exploration achievement and petroleum geologic comprehensive research , demonstrate how structure controls hydrocarbon accumulation. Structure controlling source rocks behaves structure controlling main source rocks’sedimentary facies, medium-large pools mainly located at center or margin of hydrocarbon generation. Structure controlling palaeo-karst reservoirs ,reef and beach facies reservoirs, fault and fracture reservoirs. Structure controlling palaeo-uplift, and palaeo-uplift controlling hydrocarbon migration, active reservoirs’forming, palaeo-structure traps forming. Structure controls distribution of mudstone and gypsolith, controls preservation. Structure controls hydrocarbon conducting, structure traps forming and hydrocarbon accumulation. Whether or no, Structure controls total process of basin forming-source rocks’generation- hydrocarbon accumulation. It is direct effect results of structure movements that large traps’ conditions, conducting migration conditions, high quality preservation. source rocks’condition and reservoirs’ condition are the indirect effect results. In the last analysis, “source rock controlling theory”, “high quality reservoir mainly controlling theory”, “palaeo-uplift controlling theory” and “current structure deciding theory” are structure controlling hydrocarbon accumulation. There are high variability and complex mechanisms in Sichuan basin , but the regional hydrocarbon accumulation conditions are very well, such as abundant source rocks, matching process of hydrocarbon accumulation and many exploration areas. By means of integrated analysis, put forward hydrocarbon exploration direction and large-middle targets of China Petroleum and Chemical Corporation .Thus, more and more hydrocarbon proved reserve and output in Sichuan basin will be contributed to China energy industry in a long future time.

辽河坳陷东部凹陷火山岩构造裂缝形成机理研究及预测

In recent years, with the discovery oil and gas reservoirs in volcanic rocks, the exploration and development of these reservoirs have attracted widespread attention because of the urgent need for increasing oil and gas production in the world and volcanic rocks has currently become an important exploration target in Liaohe depression. The study area of this dissertation is in the middle section of the easternern sag of Liaohe depression that have been confirmed by studying structural fractures, which constitute a key factor impacting volcanic rocks reservoirs. Substantial reserves and large production capacity in the areas with widely distributed volcanic rocks are important reasons for examining volcanic rocks in the study area. The study began with classification and experimental data analysis of volcanic rocks fractural formation, then focused on the mechanism of fracturing and the development of volcanic rocks structural fracture prediction methodology.and Lastly, predicted volcanic rocks structural fracture before drilling involved a comprehensive study of the petroleum geology of this area, which identified favorable traps thereby reducing exploration risks and promoting the exploration and development of volcanic rocks reservoirs. 3Dstress and 3Dmove software were applied to predict structural fracture by combining the core data, well-logging data and seismic data together and making the visualization of a fracture possible. Base on the detailed fracture prediction results, well OuO48 and well Ou52 were drilled and successfully provided a basis for high efficiency exploration and development of fractured reservoir in the middle section of the eastern sag. As a result of what have been done, a new round of exploration of volcanic rocks was developed. Well OU48 and well OU52 successfully drilled in this area resulted in the in-depth study of the mechanism of structural fracture formation, technological innovation of structural fracture prediction of volcanic rocks , which guided to oil and gas exploration effectively and made it possible for high production of volcanic rocks. By the end of August 2005, the cumulative oil and gas production of Ou48 block were 5.1606 × 104 t and 1271.3× 104 m3 respectively, which made outstanding contributions to the oilfield development. Above all this work not only promoted exploration and structural fracture prediction in volcanic rocks in Liaohe depression, but also applied to in the low-permeability and fractured sandstone reservoir.

砂泥岩储层测井产能预测方法研究

Productivity prediction is very important in the exploration and development of oilfields. Using well log data to predict productivity is a front-line technology， which is key issue in petroleum exploration phase. The essential factors of productivity prediction is building practical models and correcting various causes to improve precision of prediction parameters. Any errors of parameters selections can affect the calculation of productivity prediction; therefore， how to improve research means and calculation accuracy is an important task of productivity prediction. Theory and case examples are deeply and comprehensively studied in the paper. Based on the theory of mud-filtrate invasion and experimental results， the damage of drilling， cementing， perforating，acidizing and fracturing were investigated. The damage depth was quantitatively evaluated by log data， based on this， the processing results of reservoir sensitivity were used to analysis quantitatively the damage of reservoir. The productivity prediction and reservoir damage were initiatively incorporated according to well logging， and the precision of productivity prediction was effectively improved. The method of NMR was explored to calculate the fluid viscosity on the basis of reservoir physical method， and the differences between the two methods were compared in the paper. From the theory fluid flow in porous media， various of theoretical models of production prediction were explored and several practical models were consided， such as productivity index method， improved productivity index method， improved Bearder method， SVM and so on. The characteristic and the application scope of these methods were studied. The inflow productivity and outflow productivity were incorporated and nodal analysis method was used to forecast wellhead yield， thus achieved scientifically production. On the applied background of conventional logging suite， the applying of special items or new logging method which is practical in the research area were studied， the logging suite was further optimized， and the precision of forecast was improved. On the basis of the modeling and the calculation of parameters， these methods were verified and analyzed， and the reconstruct principle was also built for block reservoir. The research block was processed by these methods and compared with testing data. Based on above the research， a technological system which is practical for shaly sand profiles in Shengli Oilfield was built. The system can reach commercialized degree，and satisfied the need of exploration and development of the oilfield.

东北亚构造-盆地演化及油气资源控制作用

The oil and gas potential of Northeast Asia is enormous, but the degree of exploration is very low in Northeast Asia (the degree is below 3%-10%).The reasons are as follows: First, it is relatively difficult to study the oil and gas bearing basins(OGB), which are of multiple types, in different tectonic settings, with complex geologic frameworks and with long-term geologic evolution. Secondly, because of the non-equilibrium in development of economy and regional market, application of theories and techniques and the research levels in different countries, the conclusions are not conformable, and even contradictory. Thirdly, most of the former researches were limited to one territory or one basin, and lack of systematical and in-depth study on geotectonic evolution, classification of basins, and the evaluation of hydrocarbon resources. In this thesis, integrated study of the regional tectonic feature and basin features of Northeast Asia was done, to understand the basin evolution history and the controlling action on oil and gas. Then, new conclusions are and exploration proposals are as following: 1. Geotectonic evolution in Northeast Asia: The main structural motion system in Paleozoic Era was longitudinal, and in Meso-cenozoic was latitudinal with the Pacific Ocean. The whole evolution history was just the one of pulling-apart, cutting-out, underthrusting and collision of the Central Asia- Mongolia Ocean and the Pacific Ocean. 2. The evolution characteristics of basins in Northeast Asia: mainly developed from longitudinal paste-up, collision and relaxation rifting motion in Paleozoic-Early Mesozoic Era and from underthrust, accretion, and receding of subducted zone of the Pacific Ocean in Late Mesozoic Era-Cenozoic Era. 3. The research in basin classification of Northeast Asia: According to geotectonic system, the basins can be classified into three types: intracratonic, pericratonic and active zone basin. And they can be further classified into 18 different types according to genetic mechanism and dynamic features. 4. The master control factors of oil and gas accumulation in Northeast Asia: high quality cap-rock for craton and pericrationic basin, the effective source rock and high quality cap-rock for Mesozoic rifted basins, intra-arc, fore-arc and back-arc basins. Graded exploration potential of oil and gas for basin in Northeast Asia according to 7 factor, hereby, divided the oil and gas potential of basins into 5 levels. 5. Evaluation of hydrocarbon resources: The difference of resource potential among these basins is huge in Northeast Asia. The evaluation of Mesozoic rifted basin and Pacific Ocean basin showed that the large scale rifted basin and retroarc basin(including backarc marginal sea basin) have great resource potential. 6. The writer believes that the next step should pay more attention to the evaluation of petroleum resource in Far East part of Russia and trace them. On the other hand, according to integrated analysis of oil/gas resource potential and the operation difficulty in this area, suggests that East-Siberia basin, East-Gobi-Tamchag basin, Sakhalin basin, North-Okhotck basin, West-Kamchatka basin could be as cooperation priority basins in future.

高邮凹陷陈堡及陈堡东地区油气成藏规律研究

With the development of petroleum exploration in Gaoyou Depression, both old and new areas have been the active exploration targets, so the study of petroleum accumulation is significant to the petroleum exploration in the study area and the integrated oil and gas accumulation theory. Based on hydrocarbon accumulation theory and systematical research methods and combined with the structural characteristics of Gaoyou Depression, Chenbao and East of Chenbao were selected as the study areas in this dissertation, oil and gas migration pathways, accumulation periods, as well as accumulation models were studied, and favorable exploration targets were proposed. There develop three sets source rocks, which are Tai-2 Member, Fu-2 Member and Fu-4 Member respectively. Tai-2 Member is the predominant source rock in the eastern part. Fu-2 Member mainly occurs in the northern slope, while Fu-4 Member develops in the deep depression. In the study area, oil mainly comes from Fu-2 Member of Liuwushe subsag. The lower limit of TOC is 0.4%, and active source rock mostly distributed in the south fault-step zone. The source rock in Liuwushe subsag began to generate hydrocarbon in the late of Dainan depositional stage and the threshold was 2300m. The macro and micro characteristics of reservoirs and the reservoir heterogeneity characteristics of the Fu-1 Member were studied systematicly. The results show that Fu-1 Member, which has better reservoir properties, are medium porosity-medium permeability reservoir. The reservoir permeability has good correlation with porosity connectivity. The reservoirs have strong dissolution, pores are mainly thin to medium throat, and throat radii are distributed concentratedly, the sorting is good and pore structures are homogeneous. Sandstone reservoirs whether in the plan view, interlayer or in layers have a certain degree of heterogeneity, in particular, the heterogeneity in layers directly affect and control the oil and gas migration and accumulation. By analyzing the lithology correlation of the fault walls, shale smear, cross section stress, the configuration of fracture active periods and hydrocarbon generation and expulsion periods and fuzzy comprehensive evaluation, the main faults sealing were evaluated. The results show that the faults in Chenbao and East of Chenbao had poor sealing properties in Sanduo period and could be used as the migration pathways at that time. After Sanduo period, the tectonic stress fields in the area changed largely, and, consequently, the fault properties converted from tensional shear to compressive shear, the faults changed progressively from close to open, so the faults sealing became better and were conducive to the preservation of oil and gas reservoirs. According to the seismic event suspension modes and profile configurations above and under the unconformities, combined with tectonic evolutions of the study areas, the unconformity types can be classified into truncation unconformity, overlapped unconformity and parallel unconformity and the distribution characteristics of unconformities in the plan view was also studied. The unconformity structure was divided into basal conglomerate, weathered clay and semi-weathered layer vertically in the study area and this kind of structure make unconformities to be effective oil and gas migration pathways and is significant to hydrocarbon accumulation in a parts of areas. With the analyses of typical oil and gas reservoirs in the study area, combined with the research results of pathway systems, hydrocarbon accumulation models were established and the oil and gas accumulation laws in Chenbao and East of Chenbao analyzed. The oil and gas came from Liuwushe subsag and Liuliushe subsag. The oil and gas from Liuwushe subsag mainly migrated from the structural high parts into the fault-step zone along strata in northeast direction, a part of them migrated upward into the fault-step zone and the Wubao low uplift along Wu-1 Fault in northeast direction. The oil and gas from Liuliushe subsag mainly migrated into the upper reservoirs through Wu-2 fault, and lesser oil and gas migrated into the fault-step zone because of the controls of cross-section orientation, depression center and the hydrocarbon formation tendency. The favorable exploration targets in Chenbao and East of Chenbao have been concluded: the southern fault-step zone is a favorable oil and gas accumulation zone of Liuwushe subsag, and they are fault block reservoirs where fault acted as the barriers, the main target intervals are Fu-1 Member and Fu-3 Member in palaeocene; Oil and gas in the middle and northern fault-step zone mainly laterally migrated from the south areas, and the main target interval is Fu-3 Member in palaeocene; Fu-1 Member and the reserviors above the Wubao subsag are still the focuses in future explorations. The results of this study have important guiding significance for the future oil and gas exploration.

三维VSP技术的研究及应用

Today, because of high petroleum consumption of our country, society steady development and difficulty increase in new resources exploration, deep exploitation of the existing oilfield is needed. More delicate reservoir imaging and description, such as thin layer identification, interlayer exploitation monitoring, subtle structure imaging, reservoir anisotropy recognition, can provide more detail evidence for new development adjustment scheme and enhanced oil recovery. Now, the people have already realized the 3D VSP technique more effective than the general methods in solving these aspects. But VSP technique especially 3D VSP develop slowly due to some reasons. Carrying out the research of VSP technique, it will be very useful to the EOR service. 3D VSP techniques include acquisition、data processing and interpretation. In this paper, the author carried out some researches around acquisition and processing. The key point of acquisition is the survey design, it is critical to the quality of the data and it will influence the reservoir recognition as follows. The author did detailed researches on the layout pattern of shot point and geophone. Some attributes relate to survey design such as reflectivity, incidence angle, observation area, reflection points distribution, fold, minimum well source distance, azimuth angle and so on are studied seriously. In this geometry design of 3D-VSP exploration in deviated wells, the main problems to be solved are: determining the center position of shots distribution, the effect of shots missing on coverage areas and coverage times，locating the shots and receivers of multi-wells. Through simulating and analyzing, the above problems are discussed and some beneficial conclusions are drawn. These will provide valuable references to actual survey design. In data processing, researches emphasize on those relatively key techniques such as wavefield separation, VSP-CDP imaging, the author carried out deep researches around these two aspects. As a result, variant apparent slowness wavefield separation method developed in this article suit the underground variant velocity field and make wavefield separation well, it can overcome reflection bending shortage aroused by conventional imaging method. The attenuateion range of underground seismic wave is very important for amplitude compensation and oil/gas identification.In this paper, seismic wave attenuateion mechanism is studied by 3D-VSP simulateion and Q-inversion technique. By testing with seismic data, the method of VSP data attenuateion and relationship of attenuateion attribute variant with depth is researched. Also the software of survey design and data processing is developed, it fill the gap of VSP area in our country. The technique developed applied successfully in SZXX-A Oilfield、QKYY-B Oilfield、A area and B area. The good results show that this research is valuable, and it is meaningful to the VSP technique development and application of offshore oil industry and other areas in our country.

陆地三分量三维地震勘探技术研究与应用

With the development of oil and gas field exploration, it becomes harder to search new reserves. So a higher demand of seismic exploration comes up. Now 3C3D seismic exploration technology has been applied in petroleum exploration domains abroad. Comparing with the traditional P-wave exploration, the seismic attributes information which provided by 3C3D seismic exploration will increase quickly. And it can derive various combined parameters. The precision of information about lithology, porosity, fracture, oil-bearing properties, etc which estimated by above parameters was higher than that of pure P-wave exploration. These advantages mentioned above lead to fast development of 3C3D seismic technology recently. Therefore, how to apply the technology in petroleum exploration field in China, how to obtain high quality seismic data, and how to process and interpret real data, become frontier topics in geophysical field nowadays, which have important practical significance in research and application. In this paper, according to the propagation properties of P-wave and converted wave, a study of 3C3D acquisition parameters design method was completed. Main parameters included: trace interval, shot interval, maximum offset, bin size, the interval of receiving lines, the interval of shooting lines, migration aperture, maximum cross line distance, etc. Their determination principle was given. The type of 3C3D seismic exploration geometry was studied. By calculating bin attributes and analyzing parameters of geometry, some useful conclusions were drawn. With the method in this paper, real geometries for continental lithology stratum gas reservoir and fractured gas reservoir were studied and determined. In the static method of multi-wave, the near surface P-wave, S-wave parameter investigation method has been advanced, and this method has been applied for the patent successfully; the near surface P-wave, S-wave parameter investigation method and the converted refraction wave first arrival static techniques have been integrally used to improve the effectiveness of converted wave static. In the aspect of converted wave procession, the rotation of horizontal component data, the calculation of converted wave common conversion bin, the residual static of converted wave, the velocity analysis of the common conversion point (CCP), the Kirchhoff pre-stack time migration of converted wave techniques have been applied for setting up the various 3C3D seismic data processing flows based on different geologic targets, and the high quality P-wave, converted-wave profiles have been acquired in the actual data processing. In the aspect of P-wave and converted-wave comprehensive interpretation, the thoughts and methods of using zero-offset S-wave VSP data to calibrate horizon have been proposed; the method of using P-wave and S-wave amplitude ratio to predict the areas of oil and gas enrichment has been studied; the method of inversion using P-wave combined with S-wave has been studied; the various P-wave, S-wave parameters(velocity ratio, amplitude ratio, poisson ratio) have been used to predict the depth, physical properties, gas-bearing properties of reservoirs; the method of predicting the continental stratum lithology gas reservoir has been built. The above techniques have all been used in various 3D3C seismic exploration projects in China, and the better effects have been gotten. By using these techniques, the 3C3D seismic exploration level has been improved.