Reservoir Sensitivity And Influencing Factors In Baikouquan Formation Of Triassic In Mahu Depression

The Triassic formation lithologic reservoir in mahu sag is the main field of petroleum exploration in xinjiang oilfield in recent years.However,due to the poor physical property,large oil and gas content difference,unstable production,the sensitivity characteristics of the reservoir require in-depth analysis,and effective reservoir formation mechanism needs to be clarified.For Marjorie lake depression group Triassic baikouquan mouth north-mahu slope area and west-mahu slope area of reservoir sensitivity characteristics of complicated characteristics,reservoir control factors and effective reservoir formation mechanism research,from the gap analysis of the reservoir characteristics,combining previous research achievements of sedimentary microfacies in the reservoir,explore the influence of reservoir sensitivity characteristics of the main control factors,for reasonable exploitation,production design,etc.To provide experimental basis for the establishment of development plan.The results show that :(1)the main reservoir in ma 18 well is superior to ma 131 well and fengnan 4 well,and the reservoir in aihu 2 well is the worst.(2)the interstitial material in the reservoir is mainly composed of iran-montmorelse minerals,and the oil layer near the source shows weak water sensitivity,while the local well area shows medium to strong water sensitivity.The reservoir in the vicinity of the source shows medium to strong stress sensitivity,and the local well shows strong stress sensitivity.(3)sedimentary microfacies are the main factors that control the reservoir micropore structure,reservoir property,and interstitial material type and content.The shape and composition of material source and different transport distance and method;The type and content of interstitial material affect the distribution and content of sensitive mineral.(4)the sedimentary environment and the type and content of interstitial substances are the main factors affecting the water sensitivity of conglomerate reservoirs,while the speed sensitivity is controlled by the content and degree of colinite and the stress sensitivity is controlled by compaction,reservoir property and grain arrangement.(5)reservoirs with different sensitivity types and different sensitivity strength show different seepage degree;Clay mineral composition,content and occurrence control water damage degree,and also cause water saturation change in relative permeability curve.(6)the combined method of "core location immersion + clay dilatometer" is used to evaluate the water sensitivity characteristics of the highly water-sensitive core,which is convenient to observe and compare the micro-changes of the reservoir before and after fracturing fluid immersion,so as to help optimize fracturing fluid intuitively.