Design And Structural Optimization Of A Small-sized Azimuthal Gamma Geosteering Tool With Drilling

In order to solve the technical problems of improving the drilling encounter rate of horizontal reservoir,reducing mudstone crossing and extending the length of horizontal section,this paper,with the support of the school-enterprise cooperation project of Chuanqing Drilling of CNPC,takes the small-sized drilling orientation gamma geosteering tool as the research object and carries out the tool structure design,tool performance analysis(static and dynamic characteristics,erosion resistance and geological response characteristics)and tool structure optimization under the small-sized space.The design of tool structure,analysis of tool performance(static and dynamic characteristics,erosion resistance and geological response characteristics,etc.)and optimization of tool structure were carried out to provide theoretical basis and reference for its further promotion and application in practical engineering.The main research work is as follows.(1)To summarize the characteristics of geosteering technology and tool parameters by investigating the drilling geosteering tools,and to provide data basis for the tool design scheme.(2)Based on the principle of natural gamma radioactivity of rocks,research and analysis on the distribution law of natural gamma intensity of strata,the mechanism of geosteering with drilling azimuth gamma and the influencing factors of geosteering with drilling azimuth gamma measurement,and provide theoretical basis for the analysis of geological response characteristics of tools.(3)To complete the design of mechanical structure,water eye parameters and measurement system of small size geosteering tool,to determine the combination of instrument hookup,communication mode and working mode,to form the overall scheme design parameter combination,and to provide the basis for tool performance analysis and structure optimization.(4)To complete the analysis of static and erosion characteristics of small-sized geosteering tools,and to study the influence of different combinations of design parameters(mechanical structure parameters,water-eye structure parameters)on tool performance(static analysis and hydrodynamic analysis,so as to provide a basis for further optimization of tool design.(5)To complete the analysis of geo-response characteristics of small-sized geo-guided tools,study the components of geo-response characteristics of tools,establish the characterization relationship between geo-response characteristics and instrument detection characteristics,establish the MCNP calculation model of instrument detection characteristics based on Monte Carlo theory,study the influence of functional components parameters on the geo-response characteristics of tools,and provide the basis for further optimization of tool design.(6)To further optimize the design of the small size geosteering tool so that the overall performance of the tool(mechanical strength,erosion resistance and measurement performance)can be improved;to conduct mechanical performance tests using the tool structure samples,the results show that the tool is structurally intact and undamaged under complex working conditions.