Features And Prediction Of Volcanic Reservoir Of Fengcheng Formation Of Permian In Wuxia Area

The volcanic rock reservoir can be classified according to its eruption ways, types ofreservoir space and main factors of hydrocarbon accumulation.It is significant to analyzeevery sort of reservoir by studing its geological genetic model,lithofacies,physical propertiesand the characteristics of fluid distribution for comprehensive prediction of volcanicreservoir.This paper takes the example of the volcanic reservoir of Fengcheng group of Permianin wuxia area of Junggar Basin. From the four major aspects,the reservoir geologicalcharacteristics, geophysical simulation with technical method optimization, comprehensivereservoir prediction, hydrocarbon accumulation rules and favorable zones prediction,geological characteristics and prediction method of the fissure eruption of primary poretype reservoir are studyied.Main contents are as follows:1. The study about the geological characteristics of volcanic rock reservoir in Wuxiaarea: analysis tectonic background,formation characteristics and volcanic eruption pattern ofPermian in wuxia area, rock types and lithofacies characteristics of Fengcheng group volcanicrock are described. through analyzing the formation mechanism and physical characteristicsof the space in volcanic rock reservoir, the conceptional model of primary pore type reservoircan be established.2. Geophysical simulation and technical method optimization:by analyzing logresponse characteristics and seismic response characteristics of volcanic rock reservoir, thisvolcanic rock reservoir has high resistivity, high natural gamma and high acoustic time, lowdensity, high amplitude, low frequency. Through the forward modeling,it reveals the seismicresponse characteristics of different filling degree of pore in the lava breccia tuff. By SEC analysis, logging lithology interpretation chart, seismic lithologic interpretation chart andseismic properties interpretation chart are established.So it provides the basis for theidentification of volcanic rock, distribution prediction of different filling degree of volcanicrock, the prediction methods of petrophysical properties of volcanic rock.3. Comprehensive prediction of volcanic reservoirs of Fengcheng Formation in Wuxiaarea: The paper conducted to layer interpretation based on seismic-geologic precisely layerlabeling, figured out the distribution of volcanic ven by the results of fault interpretation andvolcanic eruption patterns, recovered palaeogeomorphology by sequence stratigraphy theory,finished logging lithologic interpretation by well log curves threshold set by logginglithologic interpretation chart analysis, predicted the distribution characteristics of volcanicrocks with different pore filling degree by seismic attribute analysis and modeling techniques,established the native porosity type reservoir lithofacies model of fissure eruption, establishedporosity interpretation model to make porosity well logging interpretation by density welllogging curves on basis of core analysis, predicted fracture distribution in studied area byAFE interpretation technique, predicted porosity distribution according to the correlationbetween wave impendence and porosity, predicted permeability distribution by the correlationbetween permeability and porosity, established the native porosity type reservoir physicalproperty model of fissure eruption according to the prediction of porosity and permeability,predicted oil and gas distribution by extract the quality factor attributes of the target layersand futher established the native porosity type reservoir liquid model of fissure eruption.According to setting on evaluation criteria，high quality reservoirs are evaluated, and thefavorable exploration targets are proposed.