Study On Acoustic And Resistivity Imaging Log Data Interpretation Processing Methods And Deovelopment Of Software

With the rapid development of imaging logging, micro-resistivity scanning and circumferential borehole acoustic imaging logging combined with conventional logging, dipole shear wave logging, NMR logging datas comprehensive analysis, plays an important role in more and more complex, subtle and unconventional oil and gas reservoirs exploration. It can get a variety of rich information on circumferential and radial directions of bolehole, can be oil and gas exploration and development of effective solution to a problem: fracture identification and evaluation of high resolution thin evaluate, sedimentary environmental analysis, stratigraphic analysis and geological structure within the structure of explanation. In addition, forecasts for gas reservoir storage, to prevent lost circulation, well collapse, perforation location detection, hole density and so provide a basis for engineering applications. To this end, full use of the rich micro-resistivity scanning and circumferential borehole acoustic imaging logging borehole information, geological structure dip calculation , stratification analysis and fracture and vug parameters'automatic calculation has a very large theoretical significance and application value.In view of the import or self-development image tools, integrating the needs and field experience, learn and analyze the advantages and disadvantages similar software at home and abroad, has developed a imaging processing and interpretation software with its own characteristics, can handle STAR, CBIL, FMI, EMI, XRMI, CAST and other imaging equipment logging data, including preprocessing, image generation, geological dip, stratification analysis, resistivity scale, porosity spectral analysis, image processing and fracture parameters'automatically computing.This article discusses the interpretation of basic principles of each functional module, the key technology and algorithm improvement, and result evaluation. Schlumberger logging company's Geology and Atlas logging company's eXpress are the basis of algorithm. Preprocessing module includes information on the acceleration correction of the borehole, voltage correction (EMEX correction), deep power button alignment, bad power button correction, equalization, phase correction, bias correction, caliper scale . Image generation module for static and dynamic image enhancement, including RGB calibration, histogram specification, histogram matching. Module using the dip method to solve all the relevant contrast, the best correlation point electrode, then the least square method to fitting the best plane, and the device coordinates into real coordinates, and further request get to level occurrence elements. Resistivity scale module according to GR curve associated contrast, the conventional LLS correction to the image depth of lines; combination of Emex curve, convert the LLS curves corrected into theoretical current CLLS; statistics generated power button mean curves, which match the vertical resolution obtained with LLS (good correlation); calculated by statistical fitting Ave2LLS to CLLS scale relations, while Ave2LLS scale generated Sres, for quality control. Porosity spectrum analysis module will scale the resistivity after the saturation by the classical formula Archie porosity, then a certain window length statistical distribution histogram of porosity, using a large law (OTSU) to determine the primary and secondary pore domain cutoff point and output values of primary and secondary porosity. Fracture and vug parameter calculation module according to cracks, holes reservoir has a "background of high resistivity, low resistivity target" feature, its corresponding histogram data corresponding to the maximum peak of carbonate bedrock, such as sub-peak corresponds to crack need to identify targets. Therefore, select the appropriate threshold value, the crack resistance of target low-out from the image segmentation and image processing algorithms are based on low-resistance target hole fracture area, the percentage of parameters, length, width and other parameters to half of the image quantitative evaluation.In addition, in-depth study of image enhancement, segmentation algorithm, used in the image generation, calculation of fracture parameters, the primary and secondary porosity module .the final set on the image enhancement algorithm using histogram specification and the group histogram matching method to achieve the mapping rules, to eliminate the traditional histogram equalization in the treatment of low gray level distribution of image-intensive specific enhancement difficult to control, making the combined gray-scale image layered bad enough losing image details, etc., to improve effect is obvious; the fracture parameters calculation, based on image processing technology to provide a variety of segmentation methods to meet the needs of different image processing, not only calculate the crack density, crack length, crack width and other parameters, and the hole can be realized Calculation and statistics ; porosity, large law spectrum module output of the original segmentation threshold value, secondary porosity, select the threshold of the ideal and effectively.Evaluated logging data of 10 boleholds by using the developed software, to verify the software of reliability and practicality, can promote the use of oil.