Geological Analogy Expert System of Oil-Generating Depressions

The geologic analogy expert system of oil-generating depressions (GAESOD) constructed on IBM 386 by using GCLISP language is a tool-type expert system for geologic analogy .GAESOD consists of eight parts: (1) illustrating module of system; (2) general controlling module; (3) knowledge base; (4 (reasoning module; (5 )data base; (6)explanation module; (7)gaining and managing module of knowledge; (8) managing module of data base .There are 36 known models of oil-generating depressions of the eastern part and the continental shelf of China in the knowledge base .Three values,such as resemblance coefficient ,certainty factor and fine-poor coefficient ,will be acquired if this system is applied to any two on-generating depressions .Finally,GAESOD are applied to the analysis of some data from Xichang depression ,Hepu basin and the conclusions from this system are consistent with the results from geologic experts.

Three Practical Methods for Analyzing Slope Stability

Since the environmental capacity and the arable as well as the inhabitant lands have actually reached a full balance, the slopes are becoming the more and more important options for various engineering constructions. Because of the geological complexity of the slope, the design and the decision-making of a slope-based engineering is still not practical to rely solely on the theoretical analysis and numerical calculation, but mainly on the experience of the experts. Therefore, it has important practical significance to turn some successful experience into mathematic equations. Based upon the abundant typical slope engineering construction cases in Yunnan, Southwestern China, 3 methods for analyzing the slope stability have been developed in this paper. First of all, the corresponded analogous mathematic equation for analyzing slope stability has been established through case studies. Then, artificial neural network and multivariate regression analysis have also been set up when 7 main influencing factors are adopted.

Preliminary Prediction and Evaluation on Source Rock in Low Exploration Basin—A Case Study from the Northeast Depression,South Yellow Sea Basin,East China

Low exploration activity fields（e.g.,deep formation,deep water,and new exploration areas） are of great importance for petroleum exploration.The prediction of source rocks is critical to the preliminary evaluation of low exploration activity fields,which will determine the early strategic electoral district and decision of exploration activity.The northeast depression is a new exploration area at the South Yellow Sea basin at present.Based on lots of seismic data in the study area and a few of well data in adjacent homologous depression,the early evaluation of source rock in the northeast depression was finished by comprehensively using the techniques of geological analogy,geophysical inversion and basin modeling,and an integrated methodology about preliminary evaluation of source rocks to low exploration activity fields is also presented.The methodology consists of three aspects：（1） prediction of the main formation of major source rocks,based on analogy analysis of seismic reflection characteristics and quality of source rocks in adjacent homologous depression;（2） method of seismic attribution to determine the thickness of source rocks;and（3） prediction of vitrinite reflectance,based on basin modeling technique to determine the maturation of source rocks.The results suggest that the source rock of the Taizhou（泰州） Formation is the most important interval for hydrocarbon generationin the northeast depression,which is characterized as high TOC,fine OM type,huge thickness,and high maturity.The western subdepression is the most important hydrocarbon kitchen in the northeast depression.