Processing And Analysis Of RIB Well Logging Data

RIB is a second generation radial well cementing evaluation instrument, absorbed a number of electrical, computer, micro circuit, transducer and so on the latest development of the technology, improved the cementing evaluation method, overcome the early logging tool in casing around the vertical, radial cement bond quality quantitative assessment provides many limitations.This paper describes the processing and analysis of RIB well logging data from two aspects of theoretical derivation and practical application. This paper mainly from the rib of logging technology development, research status at home and abroad, and the research significance of characteristics corresponding casing rib data were analyzed, including the waveform feature in a variety of situations and characteristics of each sub waveform characteristics and cement relations carries on the elaboration, this part focuses on the analysis of the waveforms of low density cement, slim hole, and the lithology of the formation wave effects are discussed; and then discusses the methods and evaluation criteria of rib logging data to evaluate cementing quality, including the logging data to evaluate cementing quality and the rib logging evaluation standard.This research has solved the existing RIB logging cementing quality evaluation problem, the main understanding about a few points:1) RIB logging data by influence factors, including:tool eccentricity, WOC time, lithology, distance, cement density and ring thickness, size of casing, double-layer or multilayer casing, micro ring gap, gas invasion factors. Therefore, in the evaluation of the cementing quality by using RIB logging data, must consider the measurement environment and casing size and other factors, in order to ensure the same standards of cementing quality evaluation, improve the reliability of evaluation.2) Cementing in the slim hole drilling under the condition of multi microannulus exists. RIB data is sensitive to the channel or groove, and has a certain reaction to the micro ring gap. Using these features, CBL/VDL and other data can be used to effectively identify the micro ring gap.3) Compared with the high density cement, the casing wave of low density cement is slightly higher, but not obvious at the interface, which can be ignored. When the cement thickness is greater than 15mm, the casing wave amplitude is not affected by the increase of cement thickness or the decrease of the ring gap width. Through numerical simulation, fluid systems annulus clearance variation of relationship chart to correct the actual situation can help effectively under the condition of low density cement cementing quality evaluation.