The Research Of The Method For Horizontal Well Logging Interpretation Of Braid River Sedimentary Deposits

The exploit technique of horizontal well logging is expanded and applyed extensively,especially for the gas field of low permeability dense sandstone reservoir in Sulige,and it is also means that the demand for horizontal well logging interpretation is increasingly higher,but it is faced difficulties when the well logging which is based on bristle model to apply in the horizontal well logging interpretation.As for the shortage of core data and the corresponding of well logging principle,it is not only hard to develop horizontal well interpretation work,but also urgent for gas field production to judge the accuracy of horizontal well logging interpretation,timely adjust the well track.As for the difficulties of horizontal well logging faced,this research is through the means of a fine survey of outcrop,GR analog and well field geological modeling,apply comprehensively the study of sedimentary geology,mineral petrology,reservoir configuration analysis and logging interpretation principle theories,method and techniques,conduct a systematic study on the lower part of Shihezi 8 member's low porosity,low permeability and tight sandstone which is located in Qianlishan section,northern part of the Ordos Basin,the outcrop GR logging response pattern is established to combine with well area geological modeling to interpretate the well 25-31 group which is located in the east of Sulige.Finally obtain the following knowledge:(1)Based on the study of petrologic characteristics,configuration characteristics and sedimentary architecture of sedimentary facies in the lower part of Shihezi 8 member in Qianlishan section,northern part of the Ordos Basin,combines the previous research to get the systematic analysis which assume the lower part of Shihezi 8 member in Qianlishan section developing near-source sandy braided river deposits.(2)Though the fine survey and description of the lower part of Shihezi 8 member,identify a total of 5 categories,17 lithofacies and the development of various scale erosion surface.In addition,there is a high content gravel in the whole study area,gritstone and medium-grained sandstone mostly contain gravel(Pebble content <5%).(3)Though the fine survey of outcrop in study area and according to the orders and characteristics of the interface level,identify and delineate the 6 kinds of configuration unit,respectively is the channel,longitudinal sand bars,horizontal sand bars,diagonal bar,flood plain and fall-siltseam.(4)Though a large scale of GR analog logging and physical properties,outcrop section in the study area mainly developed sandy septal interlayer and argillaceous,silty interlayers and the interlayer field GR response are analyzed,summarize the outcrop interlayer GR logging response pattern and determine the braided river sedimentary sandbody superimposition and the connection.(5)Though the use of a new standardized approach,the well log data were standardized,well logging lithology interpretation chart model was established with the help of the lithologic character-logging association.Though the chart of 26-31H1 in the east of Sulige of horizontal well core calibration logging,a geological model of well area was established.Finally,through the field logging response model and well geological model which under the constraint of horizontal well logging interpretation,identify the target layer in horizontal wells of 3 groups folder layers.