Application of Element Logging in Horizontal Well Geosteering of Marine-continental Transitional Shale Gas
In Henan Province,shale gas is most enriched in marine-continental transitional sediments,which have the characteris-tics of frequent interbedded lithology,small thickness of single layer and rapid change of longitudinal lithology.Due to the sedimentary characteristics and micro-structures developed in some areas,it is very difficult to identify the thin layers and determine the bit direc-tion.To solve this problem,the element logging data of quality shale gas layers in study area was used for fine characterization of target thin layers by means of statistical analysis.It was proposed to establish the element intersection charts of sandstone,coal and mudstone by virtue of the relationship between the element contents of Si,Al,Na,Fe,S,K,Mn and Ti,and to establish the quantitative model while drilling depending on the relationship between the element combination of Ba,Ti,Ca,and Sr and depth.The element intersec-tion charts were used to identify target thin layers,in order to provide an accurate basis for window-entering of horizontal well,and the quantitative model while drilling was used to determine the bit direction.This technology has been applied in the middle-deep shale gas horizontal well in central Tongxu uplift,and good results have been achieved.
marine-continental transitional faciesmiddle-deep shale gaselement logginghorizontal well geosteering
万方数据
维普
