Method and system for correcting saturation of oil and water in sealed coring well on basis of mathematical statistics

Abstract

The invention relates to a method and a system for correcting saturation of oil and water in a sealed coring well on the basis of mathematical statistics and relates to the technical field of oil and gas field development. The method comprises steps as follows: S1, rock core samples with different rock properties from different horizons of the sealed coring well in a research region are selected, oil and water saturation values of each sample are tested and measured, and abnormal data in measured data are deleted; S2, influence factors causing loss of the oil and water saturation are determined according to the measured oil and water saturation values of each sample; S3, the determined influenced factors are corrected. Main reasons causing deviation of actually measured saturation and original stratum saturation are determined on the basis of analysis of the influence factors causing saturation loss of the oil and water of the sealed coring well, the change rule of oil and water vaporization of rock cores are discussed from the view of mathematical statistics, the true value of oil and water saturation under the condition of original stratum can be effectively recovered, and important basic data are provided for evaluation of oil-bearing property of the reservoir and research of residual oil distribution rules.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to a method and system for correcting the oil-water saturation of a closed coring well based on mathematical statistics. Background technique [0002] With the continuous deepening of domestic oilfield exploration and development and the continuous rise of comprehensive water content in old oilfields, the accurate evaluation of water-flooded layers has become a key technical problem to be solved in controlling water, stabilizing oil, increasing reserves and tapping potential in various oilfields. Reservoir oil-water saturation data is an important basis for judging the water flooding level of oil layers, analyzing the distribution of remaining oil, and formulating reasonable development plans. In order to obtain oil-water saturation data under real formation conditions, a closed coring method is usually used to keep the original state of the formation as much a...

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Problems solved by technology

The experimental operation of the former is complicated, and the quality requirements of the measured samples are relatively high. Generally, only the influence of a single factor is considered, and the whole process of saturation loss cannot be simulated. Moreover, for the saturation correction of a large number of core samples, the high test cost and low The correction efficiency is the biggest shortcoming of this method; the latter determines the geological and reservoir factors that affect the loss of oil-water saturation for a specific oil and gas reservoir type, and optimizes the characterization parameters to establish a regional empirical formula for saturation correction. On the one hand, this method lacks theoretical basis , the applicability is better for specific oil and gas reservoirs, but the portability and popularization are not strong; on the other hand, the error of the correction results is relatively large, which cannot meet the accuracy requirements of high water cut period or complex oil and gas reservoir saturation correction

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