MIT-MTT Casing Damage Detection Technology And The Three-dimensional Imaging Software Development

At a certain stage of oilfield development, the casing within the oil and water Wells will be serious increasingly. At present, what used to examine the downhole string damage of logging methods mainly includes mechanical caliper method, ultrasonic method, electromagnetic method, etc. According to different detection methods, a series of testing instruments appear on the market. This article mainly discusses the Mult-Finger Imaging Tool logging technology (MIT) and Magnetic Thickness Tool imaging logging (MTT) combining the logging technology. And Introduces the their respective characteristics and corresponding processing software This text describes their work principle in detail. MIT instrument can record different multiple independent azimuth caliper curves, MTT instrument record the thickness curve. The combination logging of MIT-MTT can be examined to detect on casing damage effectively. This paper describes the characteristics of casing damage and summarizes the types of casing damage. And concludes casing damage data processing procedure of MIT-MTT, elaborates on how to detect casing damage.Due to the nature of the downhole casing of the various data, we should steer clear of coupling parts so as to avoid misjudgment downhole casing damage status when analyze various data which back to the surface. This paper analyzes and sums up the two instruments collar type, according to the change of the center diameter compared with the surrounding normal data, using the mean square error size so as to distinguish the different coupling type corresponds to the different curve graph. In the process of image processing, we do some corresponding processing to the shadow which above the collars. This makes the maximum guarantee of casing damage data real and effective. Calculating casing thickness by MTT, we use the right triangle method and the polar coordinates method in mathematics which links every isolated information and find its inherent regularity. Due to the change of setting curve frequency, we found the link between the amplitude and frequency, certain mathematical corresponding relationship have been established.The limitations of expressing the test data well explain the wrapped phase.In the later process of data processing,we try to achive unwrapped phase which let the real return and avoid the misjudgment of casing damage analysis effectively. According to the formula of calculating casing thickness, we ensure the casing thickness information true and reliable in certain situations.Casing damage data information, graphic, three-dimensional makes us examine the downhole casing damage status more intuitive, visual. For the3d drawing software of casing damage, we find some industy softwares such as CAED、3Dmax、Pro/Enginee are manually determined model, more complicated after some research. In order to design the3d stereogram independently, we use OpengGL technology and program in c#language and develop MIT-MTT three-dimensional mapping software of casing damage. This obtain good effect which used in the oil field instance.