Method for identifying in-place oil display in presence of drilling fluid solid-state fluorescent additive

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 mud logging engineering and fluid nuclear magnetic resonance, in particular, the invention relates to a method for identifying formation crude oil display under the condition that solid fluorescent additives exist in drilling fluid. Background technique [0002] Currently, there are two methods for identifying formation crude oil in the presence of solid fluorescent additives in drilling fluids: one is the gas detection method based on drilling fluids, which uses gas chromatography to detect on-line the composition of all hydrocarbons and C1-C5 in the gas released from drilling fluids , judge whether the gas logging display comes from additives or formation crude oil through the curve characteristics and component characteristics; the light components of solid fluorescent additives are low, and the heavy components are high; when just added, the full hydrocarbon curve rises rapidly; Dissolution and diffus...

AI Technical Summary

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, its composition has undergone many changes, so it is difficult to distinguish and even more difficult to quantify; second, with the widespread use of PDC drill bits (Polycrystalline Diamond Compact, polycrystalline diamond compact drill bits), cuttings are in the form of powder , the surface area is large, and the oil level of cuttings in the oil layer will be greatly reduced due to severe erosion by drilling fluid, so the identification method based on cuttings has lost its basic conditions

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