2-D and 3-D processing and interpretation of multi-fold ground penetrating radar data:a case history from an archaeological site

A 2.5-D and 3-D multi-fold GPR survey was carried out in the Archaeological Park of Aquileia (northern Italy). The primary objective of the study was the identification of targets of potential archaeological interest in an area designated by local archaeological authorities. The second geophysical objective was to test 2-D and 3-D multi-fold methods and to study localised targets of unknown shape and dimensions in hostile soil conditions. Several portions of the acquisition grid were processed in common offset (CO), common shot (CSG) and common mid point (CMP) geometry. An 8×8 m area was studied with orthogonal CMPs thus achieving a 3-D subsurface coverage with azimuthal range limited to two normal components. Coherent noise components were identified in the pre-stack domain and removed by means of FK filtering of CMP records. Stack velocities were obtained from conventional velocity analysis and azimuthal velocity analysis of 3-D pre-stack gathers. Two major discontinuities were identified in the area of study. The deeper one most probably coincides with the paleosol at the base of the layer associated with activities of man in the area in the last 2500 years. This interpretation is in agreement with the results obtained from nearby cores and excavations. The shallow discontinuity is observed in a part of the investigated area and it shows local interruptions with a linear distribution on the grid. Such interruptions may correspond to buried targets of archaeological interest. The prominent enhancement of the subsurface images obtained by means of multi-fold techniques, compared with the relatively poor quality of the conventional single-fold georadar sections, indicates that multi-fold methods are well suited for the application to high resolution studies in archaeology.

The new concepts and new developments in hte theory of polymer crystallization

Recently a debate about the initial crystallization process which has not been the hotspot for a long time since the theory proposed by Hoffman- Lauritzen (LH) dominated the field arose again. For a long time the Hoffman-Lauritzen model was always confronted by criticism,and some of the points were taken up and led to modifications, but the foundation remained unchanged which deemed that before the nucleation and crystallization the system was uniform. In this article the classical nucleation and growth theory of polymer crystallization was reviewed, and the confusion of the explanations to the polymer crystallization phenomenon was pointed out. LH theory assumes that the growth of lamellae is by the direct attachment of chain sequences from the melt onto smooth lateral sides.

Impacts of anthropogenic activity on the recent evolution of the Huanghe (Yellow) River delta

Hydrological statistical data, remote sensing images, and bathymetric charts were used to study the recent evolution of the Huanghe (Yellow) River delta under human-induced interventions. It was clear that water and sediment discharge from the Huanghe River had dropped rapidly since 1970, particularly after 1986. The water and sediment discharges for the period of 1986-2000 were found to have been reduced to only 29.2% and 31.2% of those in the period of 1950-69. This was caused by human factors in the upper and middle reaches of the Huanghe River, including water diversion, damming and reservoir construction, and water and soil conservation. Based on the results from visual interpretation of processed Landsat (MSS or TMJETM+) images dated from 1976 to 2001 and two digital elevation models generated from bathymetric charts surveyed in 1976 and 1992, we found that human-induced reduction of water and sediment discharge led to coastline retrogradation, with the maximum mean recession rate of -0.51 km yr-1 over the period of 1976-98, and seabed erosion beyond the -20 m isobath between 1976 and 1992. Other impacts of human activities on the recent evolution of the Huanghe River delta, including tidal flats shrinking, artificial coastline increasing, land surface sinking and so on, were also analyzed. We found that: (i) the whole delta, including subaerial and subaqueous, has turned from a highly constructive period to a destructive phase; (ii) channelization and dredging were two of the main causes of delta destruction; (iii) land loss in the Huanghe River delta caused by submersion will be increased in the near future; (iv) the Huanghe River delta was becoming more fragile and susceptible to natural hazards.

CIMS环境下基于视图对象的多库集成与互操作技术

异构分布计算环境中多数据库的集成与互操作是ＣＩＭＳ环境下信息集成的一个主要研究领域。本文在分析这方面研究成果的基础上，结合ＣＩＭＳ环境下信息集成的需求，提出了一种基于视图对象（ＶｉｅｗＯｂｊｅｃｔ）机制的多库集成与互操作技术，其基本思想是通过视图对象的机制对多种数据源中的数据进行多层抽象与封装，以满足ＣＩＭＳ环境下不同层次的应用集成需求。文中还以公共对象请求代理结构（ＣＯＲＢＡ）为基础提出了基于对象请求代理（ＯＲＢ）的多数据库集成与互操作系统ＶＯ－ＭＤＢＳ的实现机制。

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.

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.

储层评价目标驱动的地震叠前叠后综合反演方法研究

The exploration and development of natural gas in the north of Ordos basin have been one important part in China’s energy stratagem. Reservoir in upper Palaeozoic group is of lithological trap and its prediction is a crux in a series of works. Based on foregoing seismic reservoir prediction, seismic data are re-processed with some optical methods and pre-stack information is used in corresponding inversions. Through the application of diverse methods, a series of techniques for reservoir prediction come into being. Several results are achieved as flowing: 1. A set of log processing and interpretation methods is developed. Porosity, permeability and gas saturation models are rebuilt. 2. Based on the petro-physics analysis of reservoirs in upper Palaeozoic group, the equations about lithology, property, hydrocarbon and elastic parameters are established. 3. Forward modeling based on elastic wave theory is first applied in the study area and increases the resolution of modeling results. 4. A series of techniques such as pre-stack time migration and others are combined to improve the data quality. 5. Pre-stack seismic inversion is first employed in the north of Ordos Basin and brings the results of EI, P-impedance, S-impedance and other elastic parameters. 6. In post-stack inversion, logs indicating reservoir parameters are rebuilt and boost the resolution of lithology inversion. 7. Amplitude, coherence, frequency-discomposed amplitude, waveform and other sensitive attributes are extracted to describe sands distribution. Seismic modes standing for sands of P1x3, P1x2 are established. 8. Among 9 proposed wells, 8 wells encountered sands and became production wells. The output of DK13 amounts to 510,000 m3 per day. Keywords：the north of Ordos Basin, reservoir prediction, pre-stack inversion, post-stack inversion, seismic attributes．

叠前叠后联合反演技术及其在QHD32-6油田的应用研究

What geophysical inversion studied includes the common mathematics physical property of inversion and the constitution and appraisal method of solution in geophysics domain, i.e. using observed physical phenomenon from the earth surface to infer space changing and physical property structure of medium within the earth. Seismic inversion is a branch of geophysical inversion. The basic purpose of seismic inversion is to utilizing seismic wave propagating law in the medium underground to infer stratum structure and space distribution of physical property according to data acquisition, processing and interpretation, and then offer the vital foundation for exploratory development. Poststack inversion is convenient and swift, its acoustic impedance inversion product can reflect reservoir interior changing rule to a certain degree, but poststack data lack abundant amplitude and travel time information included in prestack data because of multiple superimpose and weaken the sensitiveness which reflecting reservoir property. Compared with poststack seismic inversion, prestack seismic inversion has better fidelity and more adequate information. Prestack seismic inversion, including waveform inversion, not only suitable for thin strata physical property inversion, it can also inverse reservoir oil-bearing ability. Prestack seismic inversion and prestack elastic impedance inversion maintain avo information, sufficiently applying seismic gathering data with different incident angle, partial angle stack, gradient and intercept seismic data cube. Prestack inversion and poststack inversion technology were studied in this dissertation. A joint inversion method which synthesize prestack elastic wave waveform inversion, prestack elastic impedance inversion and poststack inversion was proposed by making fully use of prestack inversion multiple information and relatively fast and steady characteristic of poststack inversion. Using the proposed method to extract rock physics attribute cube with clear physical significance and reflecting reservoir characterization, such as P-wave and S-wave impedance, P-wave and S-wave velocity, velocity ratio, density, Poisson ratio and Lame’s constant. Regarding loose sand reservoir in lower member of Minghuazhen formation, 32-6 south districts in Qinhuangdao,as the research object, be aimed at the different between shallow layer loose sand and deep layer tight sand, first of all, acquire physical property parameters suitable for this kind of heavy oil pool according to experimental study, establishing initial pressure and shear wave relational model; Afterwards, performing prestack elastic wave forward and inversion research, summarizing rules under the guidance of theoretical research and numerical simulation, performing elastic impedance inversion, calculating rock physics attributes; Finally, predicting sand body distribution according to rock physics parameters, and predicting favorable oil area combine well-logging materials and made good results.