A Method of Correcting Oil Saturation Using Core Sidewall Oil-liquid Ratio Based on Drainage Phenomenon

Abstract

The invention provides a method for correcting oil saturation based on the liquid drainage phenomenon using the oil-liquid ratio of the core side wall, including: step 1, according to the production data of the oil field, confirm that the coring well or adjacent well that needs data processing has been put into production, and there is Oil production and liquid production data; step 2, first perform porosity compression correction on the core saturation, and obtain the preliminary corrected core oil saturation and water saturation; step 3, obtain the initial discharge liquid by calculating the original oil-liquid ratio The proportion of crude oil; step 4, using the core oil saturation data and water saturation data of the core after preliminary correction in step 2, and the original oil-liquid ratio at the time of coring calculated in step 3, the corrected oil saturation is obtained . The method of correcting oil saturation based on the liquid drainage phenomenon with the core sidewall oil-liquid ratio has good operability, innovation and practicability, and is easy to popularize. It provides a feasible new method for the correction of core oil saturation.

Description

technical field [0001] The invention relates to the technical field of oilfield exploration and development, in particular to a method for correcting oil saturation by using the oil-liquid ratio of the side wall of the core during the coring period based on the liquid drainage phenomenon. Background technique [0002] At present, the factors causing the core oil saturation error are complex and diverse, there are many mathematical correction methods, and there are many auxiliary correction data available: [0003] 1. There are many factors causing the error of core oil saturation, and it is not feasible to directly correct each factor. For example, because the core needs to be stored in a -80°C freezer for several months, the water freezes into ice, causing the pores to freeze and crack. , the resulting pore change is actually difficult to correct; in addition, the volatilization of oil and water from core cutting and the volatilization of oil and water from long-term placem...

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Problems solved by technology

[0003] 1. There are many factors causing the error of core oil saturation, and it is not feasible to directly correct each factor. For example, because the core needs to be stored in a -80°C freezer for several months, the water freezes into ice, causing the pores to freeze and crack. , the resulting pore change is actually difficult to correct; in addition, the volatilization of oil and water from core cutting and the volatilization of oil and water from long-term placement of cores are also difficult to correct directly;

[0004] 2. At present, there are still geometric or mathematical methods for the correction of core saturation, but there are still some problems, for example, there is no obvious relationship between the angle offset method and the error generation factors, and the solution method of the transcendental equation is very cumbersome;

[0005] 3. After the core is taken out, the volume of dissolved gas in the crude oil will expand significantly, driving out the oil-water mixture in the core, and the core can also flow out directly after being out of the cylinder, resulting in a large loss of oil and water liquid;

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