Research On The Azimuth Response Of Electromagnetic Wave While Drilling

Electromagnetic wave resistivity measurement technology is a cutting-edge technology for oil and gas reservoir development during drilling.It uses real-time data while drilling,including physical lithology such as resistivity,gamma,neutron,and sonic waves,as well as parameters such as well inclination,azimuth,and tool surface.Explain the position of the actual reservoir and the position of the wellbore to achieve the purpose of improving the drilling rate of the reservoir.With the development of the times,the requirements for the instruments have been continuously improved,and the measurement while drilling is more and more directional and accurate,so as to adapt to the drilling requirements for more complicated formations.Thus,azimuth resistivity technology came into being.The azimuth resistivity is a relatively new measurement technology.Domestic development is relatively late,and there is a certain distance from foreign technology development.The study of the azimuth response characteristics of electromagnetic wave resistivity is aimed at studying its basic principle,its response characteristics in the formation,the response law in horizontal wells and inclined wells,and its application method in geosteering.It is conducive to the development and application of domestic instruments and is the basis for the localization of azimuthal resistivity instruments.This paper starts with the analysis of traditional resistivity instruments,describes the application principle of electromagnetic wave logging,and the measurement methods of three types of electromagnetic waves in the formation: A specific numerical calibration method for resistivity measurement is proposed,and the CPA algorithm is studied.Emphasis is placed on the analysis of the influence of strata anisotropy on measured values and on the study of corrective methods,and the establishment of stratigraphic models.In the correction of the dielectric effect,a comparative analysis of four types of curve relationships is performed and a correction template is given.At the same time,the electromagnetic wave resistivity log correction example was analyzed,and the curves of four horizontal wells were analyzed and explained.Introduce several different azimuth resistivity measuring instruments abroad,and conduct the study of the principle and the comparison of conventional resistivity and azimuthal resistivity measurement curves.A geological model was developed to analyze the azimuthal resistivity response,and the response characteristics of the directional electromagnetic wave instrument when passing through a variety of stratigraphic parameters were analyzed,as well as various factors that affect the azimuthal resistivity measurements.Finally,the analysis of traditional resistivity logging application examples is performed.Analyze the actual application of actual resistivity measurement under the reservoir.Azimuth resistivity response model was established and the simulation response was analyzed.The results show that for the resistivity CPA algorithm,the phase shift resistivity is more accurate than the CPA resistivity when the local resistivity is high.In the case of a higher resistivity than the phase shift resistivity,the CPA resistivity can withstand greater dielectric effects.Anisotropy has different effects on resistivity measurements.The dielectric constant is proportional to the resistivity measurement,the dielectric constant increases,and the corresponding amplitude ratio and phase difference of the resistivity also increase.The dielectric constant decreases and the amplitude and phase difference measurements also decrease.By comparing the conventional resistivity and azimuthal resistivity measurement curves,the comparison results show that there is a clear difference between the traditional resistivity and azimuthal resistivity measurement curves,which have obvious directionality.The azimuth electromagnetic wave resistivity instrument while drilling can predict the presence of stratigraphic boundaries and indicate the conductivity of the strata to be drilled in the case of any well inclination.It can evaluate the strata and reflect the real resistivity of the strata.The principle of azimuthal resistivity,combined with stratigraphic modeling,studies the CPA algorithm and anisotropic correction methods,and its research results establish a solid foundation for the research of azimuthal resistivity algorithms and principles.The study of the azimuth response characteristics and the analysis of the real well logging curve have a strong guiding significance for the development of the instrument and its application in the strata.