Electrical Image Log Formation Dip Processing Method Study And Software Developing

Electrical image log are used more and more in the oilfields, processed by software some geology application may be done, such as fracture identification, rock mechanical property analysis, and lithology determination. Because of laggard electrical imaging log technology inland, some oilfields have bought instruments and software abroad. For expensive price and some shortcoming in use, to develop electrical image formation dip processing software witch has independent knowledge property right, may not only meet oilfield requirement, but also fetch up the technical gap inland.The principle of three electrical image logging instruments were introduced, which included FMI developed by Schlumberger, STAR II developed by Atlas, and EMI developed by Halliburton. Some pre-processing work for electrical image logs was finished. For formation dip processing method, six-arm method was mainly researched. Finally most kinds of dip plots drawing methods were completed using Visual C++ 6.0.Four methods were introduced for six-arm dip processing, which included vector multiplying method, least square method, cluster method, and sphere projecting method. By imitating four-arm dipmeter method, vector multiplying method using partial depth displacements to define a best plane and then get the attitude of stratum. Least square method finds out the best coplanar pad combination using least square arithmetic, which provides the dip angle and azimuth. Cluster method classifies many planar combinations, and calculates the most probable dip and trend. Sphere projecting method gets the crossing point of all apparent vectors at the mapping plane, which can produce attitude of stratum.Four methods were tested by a given modeling, and correct result was gotten. A certain well data was processed using four methods, and the results keeps better accordant with the commercial software result.