Resistivity Correction And Application Of Horizontal Well In Chang 8 Reservoir Of JH Oilfield

JH oil field is located in the combination of Yi-Shaan slope and Weibei uplift.It covers seven counties and cities in two provinces and has rich reserves,among which Chang 8 reservoir is the important target of reserve submission recently.Due to the tight lithology,low porosity,low permeability and low oil saturation,the reservoirs in this area are affected by sedimentation,structure and diagenesis and show strong heterogeneity,leading to low interpretation accuracy of oil saturation.The pore structure is very complex,the characteristics of rock electrical response are not obvious,and the influencing factors of horizontal well resistivity logging are more complex,which brings difficulties to the identification of reservoir fluid.Combined with the geological,logging,seismic and drilling data of this work area,it is necessary to summarize the logging response characteristics of this area,study the influencing factors of horizontal well resistivity,correct the resistivity logging curve,improve the logging interpretation accuracy of horizontal well,and provide more real and reliable parameters for the development method adjustment of this well area.Taking Chang 8 reservoir of JH oilfield in Ordos Basin as the research object,the resistivity factors and correction methods of horizontal Wells are studied in this paper.Firstly,a systematic study is carried out based on the stratigraphic characteristics,structural characteristics and sedimentary characteristics of the study area.The stratigraphic characteristics,tectonic genesis and sedimentary characteristics of tight sandstone reservoir in this area are analyzed,and the difference of sedimentary facies in logging response and the distribution law of sand body are studied,and the main geological factors that affect the reservoir characteristics are identified.Then the reservoir characteristics,lithology,physical property,oil-bearing property and electrical relationship of the working area are studied.Analyses the composition and structure of the reservoir characteristics of the work area,distribution of pore throat structure,research different wellblock lithology,physical property,oiliness,found that they all have good correlation,combined with lithology,physical property,oiliness,logging is sensitive to the electrical parameters of the work area classification research,it is concluded that the natural gamma ray,such as sound waves are more sensitive in the region of electrical parameters,and on the basis of physical property,electric property parameters,such as the classification of reservoir.Then,according to the actual formation parameters of the working area,the influence factors of double induction of horizontal Wells are studied by using three-dimensional numerical simulation method.The surrounding rock-layer thickness and well inclination are the main influencing factors of double induction of horizontal Wells in this area.Finally,the horizontal well resistivity correction method was studied,the inversion theory was deduced,and the shortcomings of Newton method and damped least square method were analyzed.Based on the previous research results,The rationality and effectiveness of this method are analyzed theoretically,and then applied in combination with the actual data,the evaluation is good.In this paper,an interactive forward and inverse resistivity correction method is used,which has a fast inversion speed,combined with core,logging,seismic and well logging data,and fully considered the geosteering effect of borehole trajectory,and has a good application effect.A resistivity correction method suitable for the horizontal well in this work area is obtained,and more accurate reservoir parameters are provided for the horizontal well in this work area,which is beneficial to reservoir parameter evaluation and fluid identification of the horizontal well in this area.