The Well Logging Evaluation Of Carbonates

The M and B gas fields are all located in the A block structure.They are near to each other and their reservoirs belong to the same layer.The reservoir lithology is carbonate rock,and the type of reservoir space is mainly fracture-cavity.There are many types of pores in the reservoir,including intergranular pores,intragranular pores,mold pores,intercrystalline pores and dissolved pores.The porosity distribution is complex and the fractures are well developed,which made the well logging evaluation difficult.In this paper,well logging data,electro-imaging data and core data were used to evaluate the carbonate reservoirs in the M and B gas fields,and a well logging interpretation model which is suitable for this area is established.Fluid properties are identified by overriding the porosity curves,the reservoir porosity and permeability parameters are determined and evaluated,water saturation is obtained by using different models based on fracture development.The detailed evaluation of reservoir fracture development characteristics is done by picking up cracks,analyzing fracture development,evaluating the dissolved pores,counting fractures and holes.Also,the classification method of the reservoir is established.In conclusion,the model is applied to the M and B gas fields and the result is well.It has positive significance for the exploration and development of the M and B gas fields.