| The Upper Wuerhe Formation in Well Block Mahu-1 has always been the main strategic deployment area of oil and gas exploration in Xinjiang oilfield,with large production requirements and heavy production tasks.However,since 2020,the effect of new Wells put into production is not satisfactory,mainly due to the problems of large productivity difference of single well,rapid pressure drop and rapid production decline in the development process,which seriously restricts the efficient development of this reservoir.At present,the sedimentary microfacies research in this area is not detailed,and the content of clay minerals in the reservoir is relatively high,and the content of water-absorbing and expandable clay minerals such as the Aemon mixed layer is also high,resulting in poor effect after production,which has a great impact on the effective development of Mahu oil and gas resources.Therefore,it is necessary to clarify the distribution of sedimentary microfacies,types and characteristics of clay minerals,control factors and distribution rules of clay minerals,etc.,so as to realize quantitative evaluation and fine prediction of conglomerate reservoir sensitivity in the study area,provide guidance for the deployment and development of horizontal Wells,and provide support for the development test and the overall scale deployment of the reservoir.Based on previous studies,the research on the sedimentary characteristics and reservoir characteristics of the study area is improved.In the analysis of the relationship between them and the productivity of oil and gas Wells,it is more effectively demonstrated that the sedimentary facies belt controls the distribution of effective sand bodies,and there are obvious differences in physical properties,oil content and productivity of conglomerate with two different sedimentary origins,traction flow and gravity flow.On the basis of sedimentary characteristics and reservoir characteristics,combined with logging,scanning electron microscopy,X-ray diffraction and other data,a systematic study of clay minerals in the study area was carried out.The types and characteristics of clay minerals can be obtained through the analysis of X-ray diffraction experiment results and scanning electron microscopy data.The clay minerals in the conglomerate reservoir in the study area include Aemon mixed layer,illite,chlorite and kaolinite,among which the content of Aemon mixed layer is the highest,which is mainly characterized by grain surface and intergranular irregularity,followed by intergranular honeycomb,and the content of illite,chlorite and kaolinite is low.The controlling factors and distribution law of clay minerals need to esTablelish an interpretation model of clay minerals based on X-ray diffraction experimental data and well logging data to realize the interpretation of clay minerals in the whole area.Combined with the distribution and sedimentary facies characteristics of clay minerals,the controlled factors of clay minerals can be analyzed.The results show that the distribution of clay minerals in the study area is controlled by sedimentary microfacies.The content of clay minerals in microfacies of debris flow,debris flow and estuarine sand bar is higher,while the content of clay minerals in microfacies of underwater distributary channel,fan channel and remote sand bar is lower.Estuarine sand bar,debris flow,debris flow microfacies of the mixed layer content is higher,fan channel and underwater distributary channel microfacies of the mixed layer content is lower.The content of illite and kaolinite in the microfacies of the fan channel is higher,while the content of illite,kaolinite and chlorite in the microfacies of the far sand bar is lower.After identifying the distribution of clay minerals in the study area,favorable development zones were divided according to sedimentary microfacies,which provided the basis for the plan deployment of horizontal wells in the study area and the subsequent large-scale construction of production. |
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