Method and device for confirming effective motion space of shale strata tight reservoir crude oil

Abstract

The invention provides a method and a device for confirming effective motion space of shale strata tight reservoir crude oil. The method comprises the following steps: measuring the first relaxation time and a first amplitude value of nuclear magnetic resonance of a shale core sample of a shale strata tight reservoir, wherein the crude oil in the shale core sample is at saturated state; integrating the first amplitude value according to the first relaxation time, to obtain the T2 spectrum amplitude integrated value of the total accumulation space volume of the shale core sample; carrying out centrifugal operation on the shale core sample, and measuring the second relaxation time and second amplitude value of nuclear magnetic resonance of the centrifuged shale core sample; integrating the second amplitude value according to the second relaxation time, to obtain the T2 spectrum amplitude integrated value of the constraint accumulation space volume of the centrifuged shale core sample; measuring the total porosity of the centrifuged shale core sample; according to the data, confirming the effective motion space of the shale strata tight reservoir crude oil. The method and the device can achieve the technical effects of shortening the experiment time and improving the accuracy of experiment results.

Description

technical field [0001] The invention relates to the technical field of petroleum exploration, in particular to a method and a device for determining the effective movable space of crude oil in tight reservoirs of shale formations. Background technique [0002] Tight reservoirs in shale formations are the general term for tight reservoirs and shale reservoirs in shale formations. Tight oil and shale oil in shale formations refer to those whose crude oil production capacity cannot reach industrial oil production under conventional oil test conditions. These reservoirs have no commercial value in themselves and can only be successfully commercially developed after large-scale volume fracturing. The amount of geological resources of tight oil is huge, and the amount of geological resources of shale oil is even greater. Therefore, the potential for exploration and development of tight oil and shale oil is very large. With the research on tight oil and shale oil, tight oil and sha...

AI Technical Summary

Problems solved by technology

[0005] However, the NMR porosity of shale is generally smaller than the water porosity, so by T 2 The spectrum cut-off value method to determine the effective movable space of crude oil in tight reservoirs of shale formations has the following problems, that is, at T 2 There is still room for movable fluid below the spectral cutoff, so T 2 The spectral cut-off value method cannot truly reflect the effective movable space of the fluid

Further, the porosity of tight reservoirs and shale reservoirs in shale series is generally less than 10%, and the lower limit of effective porosity of proven crude oil reserves submitted by tight clastic rock reservoirs is 6%, and the porosity of shale oil recoverable The lower limit is lower, generally 4%. Therefore, in the existing technical process, the core column is first washed with oil, dried, and then saturated with water. It is difficult to meet the requirement that the shale series samples can be completely saturated with water. , so that the result of the final determined effective movable space is inaccurate

At the same time, the process of washing oil, drying, and resaturating water takes 3 months, which takes a relatively long time, and the core is also easily broken during the process of washing oil, drying, and resaturating water

[0006] For the above problems, no effective solutions have been proposed so far

Images