Comprehensive Trap Evaluation Of Southern Wuerxun Depression In The Hailar Basin

Trap is the basical and geological unit of oil-gas accumulation which is most important target of oil-gas exploration. Trap comprehensive evaluation is most basical evaluation content of resource assessment which is closely connected with oil-gas exploration and production practice. Its main purpose is trap evaluation and its relative superiority. Practice shows that, scientific and reasonable evaluation of traps is great significance to reduce the risk of exploration and improve the exploration benefit.Petroleum resources evaluation is the combination of comprehensive study on petroleum geology and modern engineering technology. Petroleum resources evaluation includes geological evaluation, resource estimation and economic evaluation. Geological evaluation is the foundation. At present, geological evaluation of trap mainly uses the methods including the geological risk probability method, fuzzy comprehensive evaluation method, the multi-information superposition method, qualitative queuing method, scoring method, expert system method. More traditional methods mainly include geological risk probability method, scoring method and qualitative queuing method.Wuerxun depression is a secondary tectonic unit of central rift zone in the Hailar Basin. The depression has the characteristics of North-South sub-depression. The study area is located in the south. N formation, T formation and D he formation is the main productive layers of Wuerxun depression. The major reservoir is located in the three formations too.By2010, the reserve traps of southern Wuerxun has reached184structural traps,336shallow structure traps. At present, the existing trap has never been assessed and optimized The purpose of the study is to do the job of geological evaluation of all the traps and resource estimation on the basis of the latest exploration and production data. On this basis, integrated classification and optimization of the trap is accomplished.The geological evaluational index is selected by collected data and previous research in southern Wuerxun in the Hailar Basin. Three kind of methods including the expert coefficient method, analytic hierarchy process and a new statistical analysis method have been used to calculate weights respectively. The three kind of weights are combined to determine the final weights of parameters, which makes evaluation standards of the trap. The Munro Carlo algorithm is used to calculate probabilistic reserves of the trap. Test data, interpretation of results and reserves parameter information of adjacent area is used to assign values for the uncertain resource parameters of each trap (including oil bearing area coefficient, effective thickness and unit reserve factor). It utilize the method of three parameters with three value, which is assigned three values including the minimum value, possible value and maximum value to oil bearing area coefficient, effective thickness and unit reserve factor. Based on reasonably evaluation standards and the result of reserves parameters value, geological evaluation of trap and resource estimation is done. Finally the two factors method is used for comprehensive classification and optimization of the undrilled trap.