Study On Data Interpretation And Experiments Of MRIL-Prime Logging

It has cost much for China to import some MRIL-P made by Hallliburton, the processing software of which is the processing and analyzing systems based on the geological situation of oil and gas aboard. Therefore there exist some analyzing and processing methods in the systems which are not suitable for the situation of China. On the other hand, the high cost of the imported software and its cost in the processing and interpretation will also increase that of NMR logging. So it is not advisable to spread this kind of logging method in China.The thesis deals with the following points:First, DPP and PETROSITE by Hallliburton are seriously anatomized. By analyzing its manners of NMR logging, it makes clear of the .cls format to form the foundation of the later data processing.It studies on the signal preprocessing method in NMR logging.The records in NMR logging are a couple of channels of spin echoes that need a filtering processing and an estimate of the signal phase, so an echo signal curve including the spin echo scope as well as noise, which is used to process the T2 spectrum inversion and so on, and a noise curve only including noise, which is used to analyze the logging quality, can be obtained. Phase correcting, smoothness stacking and filtering processing on NMR logging data is necessary when a signal curve is ensured.MRIL-P makes time but not actual logging depth as its index to record the NMR logging signals, so it is necessary to convert the time index to the actual logging depth.The NMR curve processed previously is a porosity decay line which can not reflect the porosity situation directly. So it is necessary to invert the decay line into several T2 relaxation time as well as the sizes of the corresponding porosity, that is, to invert into the T2 distribution.Second, it analyzes particularly the T2 inversion by the means combining mathematics and physics, and induces three kinds of methods: norm smoothing method and SVD method. It makes a contrastive analysis on the merits and demerits between them theoretically and experimentally. The norm smoothing method is stable and is easy to realize the non-negativity confine, also the result has a reasonable continuity and a high resolution .This method is suitable for the data inversion when SNR is above 20. SVD is fast speed and is reasonable when SNR is above 80. But it can result in the abnormality of T2 spectrum owing to the constraint of non-negativity confine although it suppresses noise excessively. Considering their differences responding to SNR, and taking into account of the relationship among the SVD coordination factorλ, norm smoothing factorαand SNR, the thesis argues that establishing the corresponding method of correction can improve the quality of the inverted results.Third, the thesis studies how to confirm the reservoir parameter of NMR porosity on the basis of T2 spectrum inversion. It studies to establish the models of NMR porosity and permeability explanation, and to ascertain the reservoir parameters such as NMR total porosity, NMR effective porosity, clay bound fluid porosity, capillary bound fluid porosity, bound fluid saturation, permeability and so on.Taking the logging research in Liaohe region for example, the thesis makes a close study on the NMR features of the reservoir rocks, establishes the NMR analysis parameters ,analysis standard and analysis models fit for the conditions of the reservoir in Liaohe and analyzes the NMR logging data by the self-developed software ,therefore to search some new favorable zones.It studies the relationship between the NMR relexation stamp and rock petrophysics property systematically, to clarify the similarities and differences between the logging results of NMR and analysis results of conventional core. It selects kinds of the rock of oil-gas reservoir to research on many aspects such as reservoir fluid NMR properties, NMR T2 response, pore size distribution, porosity, permeability, moveable fluid and T2 cutoff time and the impact of paramagnetic ion on NMR logging and so on.The reservoir water salinity and formation temperature have small influence on NMR signal. The signal intensity and value in the condition of high mineralization of water is a little smaller than that of the purified water. So the reservoir water salinity and formation temperature have small impact on the NMR logging results.As the NMR spectrum of sandstone core sample is similar to throat radius distribution, it can be converted to pore distribution or capillary pressure- saturation curve. The reduction eoefficient differs in terms of places, and it is often well night the same when in the same core sample reservoir of the same oil field.The thesis sums up the former researching findings for the internal flow in the rock pore and analyzes the oil and water relaxation law of G in rock pores. Based on a wide research on how to identify NMR fluid at home and abroad, identifying fluid is conducted by means of T1T2.,and then is converted into T2 spectrum to reduce the influence of noise. So the effect of the different T2 is perfect.Finally ,Based on the above research, MRIL-P software in a microcomputer version is developed on the platform of LEAD. When this software is applied to process and analyze the logging data, it leads to a better result compared to that through the DPP.