Tectonic Evolution and Dynamics of Deepwater Area of Pearl River Mouth Basin, Northern South China Sea

Quantitative studies on the evolution and dynamics of the deepwater area of Pearl River Mouth basin (PRMB) were carried out based on the latest geological and seismic data. The study area is generally in an extensional state during the Cenozoic. The major extension happened in the earlier syn-rift stages before 23 Ma and the extension after 23 Ma is negligible. Two rapid subsidence periods, 32-23 Ma and 5.3-2.6 Ma, are identified, which are related to the abrupt heat decay during margin breakup and the collision between the Philippine Sea plate and the Eurasian plate, respectively. The strongest crustal thinning in the Baiyun (sic) sag may trigger the syn-rift volcanism along the weak faulted belt around the sag. The Cenozoic tectonic evolution of the study area could be divided into five stages: rifting (similar to 50-40 Ma), rift-drift transition (similar to 40-32 Ma), early post-breakup (similar to 32-23 Ma), thermal subsidence (similar to 23-5.3 Ma) and neotectonic movement (similar to 5.3-0 Ma).

Seismic stratigraphy of the Qiongdongnan deep sea channel system, northwest South China Sea

Based on more than 4000 km 2D seismic data and seismic stratigraphic analysis, we discussed the extent and formation mechanism of the Qiongdongnan deep sea channel. The Qiongdongnan deep sea channel is a large incised channel which extends from the east boundary of the Yinggehai Basin, through the whole Qiongdongnan and the Xisha trough, and terminates in the western part of the northwest subbasin of South China Sea. It is more than 570 km long and 4-8 km wide. The chaotic (or continuous) middle (or high) amplitude, middle (or high) continuity seismic facies of the channel reflect the different lithological distribution of the channel. The channel formed as a complex result of global sea level drop during early Pliocene, large scale of sediment supply to the Yinggehai Basin, inversion event of the Red River strike-slip fault, and tilted direction of the Qiongdongnan Basin. The large scale of sediment supply from Red River caused the shelf break of the Yinggehai Basin to move torwards the S and SE direction and developed large scale of prograding wedge from the Miocene, and the inversion of the Red River strike-slip fault induced the sediment slump which formed the Qiongdongnan deep sea channel.

Geomorphology, sedimentary processes and development of the Zenisu deep-sea channel, northern Philippine Sea

The Zenisu deep-sea channel originates on the Izu-Ogasawara island arc, and disappears in the Shikoku Basin of the Philippine Sea. The geomorphology, sedimentary processes, and the development of the Zenisu deep-sea channel were investigated on the basis of swath bathymetry, side-scan sonar imagery, submersible observations, and seismic data. The deep-sea channel can be divided into three segments according to the downslope gradient and channel orientation. They are the Zenisu Canyon, the E-W fan channel, and the trough-axis channel. The sediment fill is characterized by turbidite and debrite deposition and blocky-hummocky avalanche deposits on the flanks of the Zenisu Ridge. In the Zenisu Canyon and the Zenisu deep-sea channel, sediment transport by turbidity currents generates sediment waves (dunes) observed during the Shinkai 6500 dive 371. The development of the Zenisu Canyon is controlled by a N-S shear fault, whereas the trough-axis channel is controlled by basin subsidence associated with the Zenisu Ridge. The E-W fan channel was probably affected by the E-W fault and the basement morphology.

Sedimentary processes and development of the Zenisu deep-sea channel, Philippine Sea

Zenisu deep-sea channel originated from a volcanic arc region, Izu-Ogasawara Island Arc, and vanished in the Shikoku Basin of the Philippine Sea. According to the swath bathymetry, the deep-sea channel can be divided into three,segments. They are Zenisu canyon, E-W fan channel and trough-axis channel. A lot of volcanic detritus were deposited in the Zenisu Trough via the deep-sea channel because it originated from volcanic arc settings. On the basis of the swath bathymetry, submersible and seismic reflection data, the deposits are characterized by turbidite and debrite deposits as those in the other major deep-sea channels. Erosion or few sediments were observed in the Zenisu canyon, whereas a lot of turbidites and debrites occurred in the E-W channel and trough axis channel. Cold seep communities, active fault and fluid flow were discovered along the lower slope of the Zenisu Ridge. Vertical sedimentary sequences in the Zenisu Trough consist of the four post-rift sequence units of the Shikoku Basin, among which Units A and B are two turbidite units. The development of Zenisu canyon is controlled by the N-S shear fault, the E-W fan channel is related to the E-W shear fault, and the trough-axis channel is related to the subsidence of central basin.

Geophysical evaluation methods for buried hill reservoirs in the Jiyang superdepression of the Bohai Bay basin, eastern China

The Jiyang superdepression is one of the richest hydrocarbon accumulations in the Bohai Bay basin, eastern China. Comprehensive seismic methods have been used in buried hill exploration in Jiyang to describe these fractured reservoirs better. Accurate seismic stratigraphic demarcation and variable-velocity mapping were applied to reveal the inner structure of the buried hills and determine the nature of the structural traps more precisely. Based on the analysis of rock properties and the characteristics of well-developed buried hill reservoirs, we have successfully linked the geology and seismic response by applying seismic forward technology. Log-constrained inversion, absorption coefficient analysis and tectonic forward-inversion with FMI loggings were applied to analyse and evaluate the buried hill reservoirs and gave satisfying results. The reservoir prediction was successful, which confirmed that the comprehensive utilization of these methods can be helpful in the exploration of buried hill reservoirs.

南海北部陆缘深水区构造演化及其资源效应

南海北部陆缘深水区（水深>300m）蕴藏着丰富的资源，我国对深水区的地质研究刚刚起步，但相关领域已成为科研热点。深水油气盆地的构造演化是油气勘探中最重要的基础性研究之一，因此针对我国南海北部陆缘深水区开展构造演化及其资源效应的研究具有重要的理论意义和实际意义。 本文利用钻井和地震资料并结合区域地质资料，重点研究了珠江口盆地深水区的结构和构造演化，取得如下创新性成果：1）首次利用半地堑分析方法系统解剖了研究区的结构、各构造单元发育特征，在此基础上指出五个有利油气运聚带；2）采用回剥法并利用最新资料进行校正，得到了研究区更为可靠的构造沉降曲线，重新划分了裂陷期和裂后期的分界，认为32Ma南海海底扩张之后裂陷作用仍在持续，直到23Ma左右才开始大规模裂后热沉降，并进一步解释了裂陷期延迟的形成机制；3）应用非连续拉张模型计算拉张系数的方程计算了研究区的壳幔拉张系数，指出了深水区地幔相对于地壳的优势伸展作用；首次运用平衡剖面技术重建了研究区的构造发育史，计算了各构造期的拉张率和沉积速率，指出研究区新生代整体呈现持续拉张，拉张系数在1.1-1.24之间；4）精细刻画了水合物钻采区的地质构造特征，建立了该区天然气水合物成藏的概念模式；建立了一套根据地震叠加速度计算流体势的方法，为水合物成藏规律的研究提供了新的思路。

提高勘探成熟区地震资料精度的方法研究

With the Oil field exploration and exploitation, the problem of supervention and enhaning combination gas recovery was faced.then proposing new and higher demands to precision of seismic data. On the basis of studying exploration status,resource potential,and quality of 3D seismic data to internal representative mature Oil field, taking shengli field ken71 zone as study object, this paper takes advantage of high-density 3D seismic technique to solving the complex geologic problem in exploration and development of mature region, deep into researching the acquisition, processing of high-density 3D seismic data. This disseration study the function of routine 3D seismic, high-density 3D seismic, 3D VSP seismic,and multi-wave multi-component seismic to solving the geologic problem in exploration and development of mature region,particular introduce the advantage and shortage of high-density 3D seismic exploration, put forward the integrated study method of giving priority to high-density 3D seismic and combining other seismic data in enhancing exploration accuracy of mature region. On the basis of detailedly studying acquisition method of high-density 3D seismic and 3D VSP seismic,aming at developing physical simulation and numeical simulation to designing and optimizing observation system. Optimizing “four combination” whole acquisition method of acquisition of well with ground seimic and “three synchron”technique, realizing acquisition of combining P-wave with S-wave, acquisition of combining digit geophone with simulation geophone, acquisition of 3D VSP seismic with ground seimic, acquisition of combining interborehole seismic,implementing synchron acceptance of aboveground equipment and downhole instrument, common use and synchron acceptance of 3D VSP and ground shots, synchron acquisition of high-density P-wave and high-density multi-wave, achieve high quality magnanimity seismic data. On the basis of detailedly analysising the simulation geophone data of high-density acquisition ,adopting pertinency processing technique to protecting amplitude,studying the justice matching of S/N and resolution to improving resolution of seismic profile ,using poststack series connection migration,prestack time migration and prestack depth migration to putting up high precision imaging,gained reliable high resolution data.At the same time carrying along high accuracy exploration to high-density digit geophone data, obtaining good improve in its resolution, fidelity, break point clear degree, interbed information, formation characteristics and so on.Comparing processing results ,we may see simulation geophone high-density acquisition and high precision imaging can enhancing resolution, high-density seismic basing on digit geophone can better solve subsurface geology problem. At the same time, fine processing converted wave of synchron acquisition and 3D VSP seismic data,acquiring good result. On the basis of high-density seismic data acquisition and high-density seismic data processing, carry through high precision structure interpretation and inversion, and preliminary interpretation analysis to 3D VSP seismic data and multi-wave multi-component seismic data. High precision interpretation indicates after high resolution processing ,structural diagram obtaining from high-density seismic data better accord with true geoligy situation.

柴达木盆地地震勘探关键技术研究

The rugged surface topography determined the seismic data acquisition construction conditions and the seismic wave explosive and receiver quality in Qaidam Basin. This dissertation systematically researched the seismic acquisition, imaging process and the attribute analysis techniques of complicated oil and gas reservoir. The main research achievements and cognitions are as follows: 1. Through the stimulation effects research and analysis from the aspect of lithologic water-containing differences, it’s specific that stable hydrous sand layer can effectively enhance the stimulation effects combined with the corresponding field tests. The seismic data S/N ratio has been improved due to the combination explosive stimulation. Through the fold number and maximum offset analyses of target horizon, the complicated geometry has been optimized and the S/N ratio of seismic data has been improved, which made an important basis for improvement of 3D seismic data. 2. It has been proved that the first arrival refraction static correction method under the model constraint of fine surface survey is suitable to the Qaidam Basin of western areas by the real seismic data processing. Although the refraction horizon of near surface has some changes in a certain extent, it’s steady basically. The refraction horizon can be continuously traced in sections, so it’s qualified for the refraction static correction method on the whole. 3. The research is based on the curved-ray pre-stack time migration techniques of rough topography, and improved the imaging precision of complex areas. This techniques adopted the constant and variable velocity scanning mode and enhanced the velocity analysis precision. The 3D pre-stack time migration techniques reasonably solved the imaging and velocity multiple solutions problems of steep-dip faults and the intersections of horizontal layers. What’s more, fine velocity analysis and mute are very important to enhance the imaging precision of the seismic data in complicated Wunan areas. 4. The 3D seismic data edge-preserving processing methods have been realized due to the image process techniques. Because this method uses the large range filter, it can attenuate the noise maximally. The faults, break points, lithologic pinchout points and lithologic body of small scale such as river will not be influenced by blur because of the edge-preserving characterization of the method which is really an effective assistant technique of low S/N ratio seismic data attribute analysis. 5. The use of spectral decomposition technique can effectively identify the reservoirs. The special geology body which will not be identified (or without obvious characters) in the seismic profile may be found through the details changes of different frequencies in the amplitude profiles.

构造复杂区变速成图方法研究

In the complex structure areas, velocity field building and structure mapping are important for seismic exploration. With the development of seismic exploration, the methods of structure mapping, reservoir prediction and reservoir description all require high precious velocity field. And more accurate depth-structure maps are required for well site design. Aiming at the problems and defects in velocity analysis and structure mapping in oil seismic exploration, the paper which is based on the studies of real data in several areas combines the theories with practical application, and analyzes the precision and applicability of several methods of velocity model building. After that, the following methods are mainly studied: the coherence inversion methods based on the pre-stack CMP gathers or stacking velocity; the interval velocity inversion methods constrained by multi-well; the Random Simulation method; 3D Image Ray Map Migration method and the structure mapping in floating datum and in fixed datum, and then we conclude the method of building high precious seismic velocity field and structure mapping with variable velocity. Firstly, the paper analyses the distributing rule of the velocity variation in the areas with complex structures in the northwest of China, then points out that velocity is a crucial factor which influences the precision of structure mapping, and the velocity variations have something to do with the shapes of the structures, the variety of lithology and so on. The key point of improving the precision of seismic velocity field is to obtain a structure mapping with high precision. We also describe the range and conditions of these methods. Secondly, by comparing many popular methods of velocity model building, we propose a new method in the use of velocity model building. The new method is more effective in velocity model building under every kind of complex condition and is worthy of spreading. At last, the paper fingers out that it is a system engineering to study variable velocity mapping in every kind of complex structure areas. Every step of the work can affect the final results. So it is important to build high efficient and practical velocity model and the flows of mapping processing. The paper builds the flows and gives some examples. The method has been applied in more than ten exploring surveys. The application proves that this method could bring good effect on researching on low-amplitude trap, reservoir prediction, reservoir description and the integrated research of oil&gas geology. Keywords: structure mapping velocity model building complex structure variable velocity media

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.

裂缝储层预测技术应用研究

In practice,many fracture reservoir was found,which has giant potential for exporation. For example,in limestone fracture reservoir,igneous rock fracture reservoir and shale fracture reservoir ,there are high yield oil wells found. The fracture reservoir has strong anisotropy and is very difficult to explore and produce.Since 1990’s,the techniques that use structure information and P-WAVE seismic attributes to detect fracture developed very rapidly,include stress and strain analysis,using amplitude,interval velocity,time-difference,azimuthal AVO analysis etc. Based on research and develop these advanced techniques of fracture detect,this paper selected two typical fracture reservoir as target area,according to the characters of research area,selected different techniques to pridect the fracture azimuth and density of target,and at last ,confirmed the favored area. This paper includes six parts:the first chapter mainly addresses the domestic and international research actuality about the fracture prediction and the evolement in ShengLi oil field,then according to the temporal exploration requirement,a research route was established; Based on the close relationship between structural fracture and the geotectonic movement and the procedure of rock distortion，the second chapter research the structural fracture predicting technique which is realized by computing the strain in every geotectonic movement ,which is by use of the forward and inversion of the growing history of structure; The third chapter discussed many kind of traditional techniques for fracture reservoir prediction,and point out their disadvantages.then research and develop the coherence volume computing technique which can distinguish from faults,the seismic wave absorbing technique,and other fracture predicting technique which is by use of seismic attributes ,such as azimuthal AVO FVO etc; The fourth chapter first establish the geological and petrophysical model by use of the existed log and drill well information, then research the variation of amplitude and seismic wave which is caused by fractures.based on it , the fracture predicting technique which is by use of variation of azimuthal impedance is researched;The fifth chapter is a case study,it selects shale fracture reservoir in LuoJia area as target,selects several kind of techniques to apply ,at last ,the fracture distribution of target reservoir and favored area were gotten;the sixth chapter is another case study,it selects limestone fracture reservoir in BoShen6 buried hill as target,selects several kind of techniques to apply,similarly favored area were gotten. Based on deeply research and development of the new techniques for fracture reservoir exploration, This paper selects two fracture reservoirs the most typical in ShengLi as targets to be applied ,good results show up a good application way ,which can be used for reference for future fracture exploration,and it can bring materially economic and social benefit.

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.

胜利勘探数据中心及勘探辅助决策系统研究

In the paper through extensive study and design, the technical plan for establishing the exploration database center is made to combine imported and self developed techniques. By research and repeated experiment a modern database center has been set up with its hardware and network having advanced performance, its system well configured, its data store and management complete, and its data support being fast and direct. Through study on the theory, method and model of decision an exploration decision assistant schema is designed with one decision plan of well location decision support system being evaluated and put into action. 1. Study on the establishment of Shengli exploration database center Research is made on the hardware configuration of the database center including its workstations and all connected hardware and system. The hardware of the database center is formed by connecting workstations, microcomputer workstations, disk arrays, and those equipments used for seismic processing and interpretation. Research on the data store and management includes the analysis of the contents to be managed, data flow, data standard, data QC, data backup and restore policy, optimization of database system. A reasonable data management regulation and workflow is made and the scientific exploration data management system is created. Data load is done by working out a schedule firstly and at last 200 more projects of seismic surveys has been loaded amount to 25TB. 2. Exploration work support system and its application Seismic data processing system support has the following features, automatic extraction of seismic attributes, GIS navigation, data order, extraction of any sized data cube, pseudo huge capacity disk array, standard output exchange format etc. The prestack data can be accessed by the processing system or data can be transferred to other processing system through standard exchange format. For supporting seismic interpretation system the following features exist such as auto scan and store of interpretation result, internal data quality control etc. the interpretation system is connected directly with database center to get real time support of seismic data, formation data and well data. Comprehensive geological study support is done through intranet with the ability to query or display data graphically on the navigation system under some geological constraints. Production management support system is mainly used to collect, analyze and display production data with its core technology on the controlled data collection and creation of multiple standard forms. 3. exploration decision support system design By classification of workflow and data flow of all the exploration stages and study on decision theory and method, target of each decision step, decision model and requirement, three concept models has been formed for the Shengli exploration decision support system including the exploration distribution support system, the well location support system and production management support system. the well location decision support system has passed evaluation and been put into action. 4. Technical advance Hardware and software match with high performance for the database center. By combining parallel computer system, database server, huge capacity ATL, disk array, network and firewall together to create the first exploration database center in China with reasonable configuration, high performance and able to manage the whole data sets of exploration. Huge exploration data management technology is formed where exploration data standards and management regulations are made to guarantee data quality, safety and security. Multifunction query and support system for comprehensive exploration information support. It includes support system for geological study, seismic processing and interpretation and production management. In the system a lot of new database and computer technology have been used to provide real time information support for exploration work. Finally is the design of Shengli exploration decision support system. 5. Application and benefit Data storage has reached the amount of 25TB with thousand of users in Shengli oil field to access data to improve work efficiency multiple times. The technology has also been applied by many other units of SINOPEC. Its application of providing data to a project named Exploration achievements and Evaluation of Favorable Targets in Hekou Area shortened the data preparation period from 30 days to 2 days, enriching data abundance 15 percent and getting information support from the database center perfectly. Its application to provide former processed result for a project named Pre-stack depth migration in Guxi fracture zone reduced the amount of repeated process and shortened work period of one month and improved processing precision and quality, saving capital investment of data processing of 30 million yuan. It application by providing project database automatically in project named Geological and seismic study of southern slope zone of Dongying Sag shortened data preparation time so that researchers have more time to do research, thus to improve interpretation precision and quality.

鄂尔多斯盆地上古生界低渗透砂岩有效储层识别与预测

Sulige Gasfield, with a basically proven reserve as high as one trillion cubic meters, is one giant gas field discovered in China. The major gas -bearing layers are Upper Paleozoic strata with fluvial-lacustrine sedimentary facies. Generally, gas reservoirs in this field are characteristic by "five low" properties, namely low porosity, low permeability, low formation pressure, low productivity and low gas abundance. Reservoirs in this field also feature in a large distribution area, thin single sandbody thickness, poor reservoir physical properties, thin effective reservoir thickness, sharp horizontal and/or vertical changes in reservoir properties as well as poor connectivity between different reservoirs. Although outstanding achievements have been acquired in this field, there are still several problems in the evaluation and development of the reservoirs, such as: the relation between seismic attributes and reservoir property parameters is not exclusive, which yields more than one solution in using seismic attributes to predict reservoir parameters; the wave impedance distribution ranges of sandstone and mudstone are overlapped, means it is impossible to distinguish them through the application of post-stack impedance inversion; studies on seismic petrophysics, reservoir geophysical properties, wave reflection models and AVO features have a poor foundation, makes it difficult to recognize the specific differences between tight sandstone and gas-bearing sandstone and their distribution laws. These are the main reasons causing the low well drilling success rate and poor economic returns, which usually result in ineffective development and utilization of the field. Therefore, it is of great importance to perform studies on identification and prediction of effective reservoirs in low permeable sandstone strata. Taking the 2D and 3D multiwave-multicomponent seismic exploration block in Su6-Su5 area of Sulige field as a study area and He 8 member as target bed, analysis of the target bed sedimentary characteristics and logging data properties are performed, while criteria to identify effective reservoirs are determined. Then, techniques and technologies such as pre-stack seismic information (AVO, elastic impedance, wave-let absorption attenuation) and Gamma inversion, reservoir litological and geophysical properties prediction are used to increase the precision in identifying and predicting effective reservoirs; while P-wave and S-wave impedance, ratio of P/S wave velocities, rock elastic parameters and elastic impedance are used to perform sandstone gas-bearing property identification and gas reservoir thickness prediction. Innovative achievements are summarized as follows: 1. The study of this thesis is the first time that multiwave-multicomponent seismic data are used to identify and predict non-marine classic reservoirs in China. Through the application of multiwave-multicomponents seismic data and integration of both pre-stack and post-stack seismic data, a set of workflows and methods to perform high-precision prediction of effective reservoirs in low permeable sandstone is established systematically. 2. Four key techniques to perform effective reservoir prediction including AVO analysis, pre-stack elastic wave impedance inversion, elastic parameters inversion, and absorption attenuation analysis are developed, utilizing pre-stack seismic data to the utmost and increasing the correct rate for effective reservoir prediction to 83% from the former 67% with routine methods. 3. This thesis summarizes techniques and technologies used in the identification reservoir gas-bearing properties using multiwave-multicomponent seismic data. And for the first time, quantitative analysis on reservoir fluids such as oil, gas, and/or water are carried out, and characteristic lithology prediction techniques through the integration of pre-stack and post-stack seismic prediction techniques, common seismic inversion and rock elastic parameters inversion, as well as P-wave inversion and converted wave inversion is put forward, further increasing the correct rate of effective reservoir prediction in this area to 90%. 4. Ten seismic attribute parameters are selected in the 3D multi-wave area to perform a comprehensive evaluation on effective reservoirs using weighted-factor method. The results show that the first class effective reservoir covers an area of 10.08% of the study area, while the second and the third class reservoirs take 43.8% and 46% respectively, sharply increasing the success rate for appraisal and development wells.