Method for identifying formation crude oil display in the presence of solid fluorescent additives in drilling fluid

Abstract

The invention relates to a method for identifying the in-place oil display in the presence of a drilling fluid solid-state fluorescent additive. According to the method, drilling fluid is used as an analytic target, and a nuclear magnetic resonance technology is used as a means, so that the influence on the in-time discovering of the in-place oil display caused by the drilling fluid solid-state fluorescent additive can be eliminated thoroughly, and the quantitative evaluation can be performed on the oil content of the drilling fluid; therefore, the use limit of the drilling fluid solid-state fluorescent additive can be released, the well drilling safety is improved, and the speed increase and the efficiency improvement can be realized. According to the method, the defects that in the conventional method can be overcome, an atlas database is required to be built and the quantitation is hard to implement, and simplicity, convenience, reliabiliyt, and easiness in operation can be realized.

Description

Technical field [0001] The invention belongs to the technical field of logging engineering and fluid nuclear magnetic resonance. Specifically, the invention relates to a method for identifying formation crude oil display in the presence of solid fluorescent additives in drilling fluids. Background technique [0002] At present, there are two types of methods used to identify formation crude oil display in the presence of solid fluorescent additives in drilling fluids: one is the gas measurement method based on drilling fluid, which uses gas chromatography to detect the total hydrocarbons and C1~C5 composition of the gas removed from the drilling fluid on-line , Through the curve characteristics and component characteristics to identify whether the gas survey shows that it comes from additives or formation crude oil; solid fluorescent additives have low light components and high heavy components; when just added, the total hydrocarbon curve rises rapidly; with the circulation of dr...

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Problems solved by technology

This method has two major disadvantages: one is that after the solid fluorescent additive is added to the drilling fluid, it must be circulated from the surface to the underground and then to the surface. Due to the impact of drilling through the oil layer, many changes have taken place in its composition, so it is difficult to distinguish and even more difficult to quantify; the second is that with the widespread use of PDC drill bits (Polycrystalline Diamond Compact, polycrystalline diamond compact drill bits), the cuttings are in the form of powder, and the surface area Due to the severe erosion of drilling fluid, the oil level of cuttings in oil reservoirs will be greatly reduced, so the identification method based on cuttings has lost its basic conditions.

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