Thick Glutenite Reservoir Evaluation and Strong Heterogeneous Quality Control Reservoir Characteristics of the First Member of Badaowan Formation in Maxi Slope,Junggar Basin
The Jurassic in the Junggar Basin is the main stratum for increasing reserves and production.Among them,the first member of the Jurassic Badaowan Formation in the western slope of the Mahu Sag(hereinafter referred to as the"Maxi slope")is mainly a low-porosity and low-permeability glutenite reservoir.The same set of reservoirs in the Maxi slope(similar tectonic,sedimentary and diagenetic conditions)have some accumulations and some have not been accumulated.It is urgent to carry out glutenite reservoir evaluation and clarify the characteristics of reservoir control.Based on the data of core,thin section,analytical test,oil test and production test,the evaluation of thick glutenite reservoir in the first member of Badaowan Formation in Maxi slope was carried out,and the reservoir heterogeneity evaluation was carried out to clarify the characteristics of non-quality control reservoir.The results show these as follows.The first member of the Badaowan Formation in the Maxi slope mainly develops thick glutenite reservoirs,which are braided channel deposits.There are four kinds of interlayers in the reservoir,including argillaceous,tight sandstone,calcareous and coal seams.The interlayers enhance the heterogeneity of the reservoir vertically.The porosity distribution range of the first member of Badaowan Formation in Maxi slope is 2.9％～18.8％,and the average porosity is 10.60％.The permeability distribution range is 0.02 × 10-3～255 × 10-3 µm2,and the average permeability is 3.29 × 10-3 μm2.The porosity distribution range of glutenite reservoir is 4.1％～15.8％,and the average porosity is 8.27％.The permeability distribution range is 0.05 × 10-3～145 × 10-3 μm2,and the average permeability is 1.24 × 10-3 μm2.The reservoir has the characteristics of small overall pore throat radius,complex pore structure,poor throat connectivity,high displacement pressure and low displacement efficiency.The relationship between reservoir space and oil-bearing property is established.The intervals with developed reservoir space and weak heterogeneity have poor oil-bearing property,while the intervals with undeveloped reservoir space and strong heterogeneity have good oil-bearing property.Reservoir heterogeneity is the main controlling factor of hydrocarbon accumulation in the thick glutenite reservoir of Badaowan Formation in Maxi slope of Junggar Basin.The data envelopment method is used to calculate the heterogeneity index of the thick glutenite reservoir in the first member of the Badaowan Formation in the Maxi slope,which is mainly between 0.621 and 0.782,which belongs to strong-medium heterogeneity.The reservoir heterogeneity index of the oil production section is 0.621～0.673,which is a strong heterogeneity reservoir.The reservoir heterogeneity index of the oil production section is 0.674～0.782,which is a medium heterogeneity reservoir.It is concluded that the reservoir heterogeneity has a controlling effect on the oil and gas accumulation of the thick glutenite reservoir in the first member of the Badaowan Formation in the Maxi slope.The oil and gas in the strong heterogeneous reservoir are difficult to escape and be preserved,and the reservoir is mainly enriched in the strong heterogeneous reservoir.
Junggar Basinwest slope of Mahu Sagsand conglomerate reservoirreservoir heterogeneityheterogeneity indexs
万方数据
维普
