The Well Logging Evaluation Study Of Tight Sandstone Gas Reservoir In Y Block Of Sulige

It has been several years since the exploration and development of Y block in the Sulige Gas Field and the exploration difficulty has been increasing.Influenced by such factors as tectonic setting,lithology and the difference of source rock gas generating intensity.The relationship between gas and water in Sulige Y zone is more complex,and logging response characteristics is not obvious.We study the petrological characteristics and the four-property relationship firstly,using logging parameters to establish logging interpretation parameter model,and exploring the methods of fluid identification and fluids rate forecast in Sulige Y block.They provide technical help for the follow-up exploration and development of the block.The research object of this paper is the Sulige Y block.Firstly,the four-property relationship and the pore structure of the reservoir are analyzed in detail.Based on the above,we analyze the data after the core-homing process,the models of porosity and permeability have been established by using the scatter method and layering method,as well as the establishment of water saturation,irreducible water saturation,shale content model accuracy is also higher.In this paper,many methods,such as replacement pressure knee point method,Phase-infiltration curve method,are used to determine the effective lower limits of physical properties of reservoir.With a variety of methods verifying each other,the lower limits of physical properties can better embody the geological characteristics of Y zone.The lower limits of porosity and permeability are 6.58% and 0.14 mD,respectively.Based on the gas and water testing analysis and common logging data,and on the basis of the four-property relationship and the established interpretation models of logging parameters such as porosity and permeability,for gas and water fluid identification are used.The results show that the recognition effect is significant for using a variety of comprehensive analytical methods.Gas production capacity is a dynamic composite index,and it is affected and constrained by many factors.We find several logging parameters that are more relevant to capacity and multivariate fitting to analyze and evaluate the production capacity comprehensively.We use the method of synthetic index and neural network to predict productivity and the results show that the prediction method has good practicality.The above research works well in practical application and have high log interpretation coincidence rate.These studies on the lower limit of effective physical properties,fluid identification and capacity prediction of the Sulige Gas field have the guiding significance and have very good practical value.