LITHOLOGY IDENTIFICATION AND PREDICTION OF IGNEOUS ROCKS BASED ON 3-D LITHOFACIES MODELLING

There is abundant natural gas resources in Changling No.1 Gas Field,most of it is accumulated in igneous rock reservoirs of Yingcheng Formation.The igneous rocks of the Formation are dominated by acidic igneous rocks with the characteristics of complex lithology.Well developed pore-vug-fracture are hard to predict.The key issue constraining the development of the igneous rock reservoirs is if the lithology can be correctly identified and predicted.Aiming at the issue of unclear understanding of the lithology and lithofacies within the area,by means of fully use of the effective data such as core,imaging well logging,cutting and conventional logging,as well as neural network technology,lithofacies interpretation model of single well is established.On the basis of it,the strategy of igneous lithofacies modeling is presented,by integrating the deterministic modeling with stochastic modeling,the 3-D lithofacies distribution model of igneous rocks is set up.The spatial distribution prediction of lithology is carried out,which provides the evidence for the development of the reservoirs.