Dual-component low-molecular-weight monoester ester group ultra-low temperature drilling fluid for polar regions

Abstract

The invention discloses dual-component low-molecular-weight monoester ester group ultra-low temperature drilling fluid for polar regions, and belongs to the technical field of polar region drilling. Butyl butyrate and amyl butyrate are used as raw materials and are compounded in proportion to obtain the dual-component low-molecular-weight monoester ester group ultra-low temperature drilling fluid. In consideration of the characteristics of frosty and bad natural conditions of the polar regions, strict environmentally-friendly requirements and deep ice layer drilling and coring, the dual-component low-molecular-weight monoester ester group ultra-low temperature drilling fluid provided by the invention has the advantages of being colorless, transparent, environmentally-friendly and low-temperature-resistant. The viscosity and density of the dual-component low-molecular-weight monoester ester group ultra-low temperature drilling fluid meet the requirements on deep ice layer drilling and coring in the polar regions.

Description

technical field [0001] The invention relates to the technical field of polar drilling, in particular to a class of two-component low-molecular monoester ester-based ultra-low temperature drilling fluid for polar regions. Background technique [0002] Carry out deep ice drilling and coring in the polar regions, obtain ice cores, ice rock interlayer samples and subglacial bedrock samples, and study the valuable information kept by these fossil-significant databases. It is of great significance to distribute and carry out geological exploration. [0003] Conventional cryogenic drilling fluids used in oil and gas extraction are not suitable for core drilling in deep polar ice formations. The main requirements of the drilling fluid used for drilling and coring in the deep polar ice layer: (1) The density of the drilling fluid can balance the overlying pressure of the ice layer and prevent the necking of the borehole; (2) During the drilling process, the drilling fluid can clean ...

AI Technical Summary

Problems solved by technology

[0005] 1. Petroleum products such as kerosene containing halogenated hydrocarbon thickeners or fluorocarbon thickeners: These thickeners are highly toxic, and most of them have been restricted by the Montreal Protocol because they cannot meet environmental protection conditions

[0006] 2. Ethylene glycol aqueous solution or ethanol solution: The viscosity of this type of drilling fluid increases significantly at low temperature, which is not applicable technically, and the drilling fluid dissolves the ice hole wall, ice core and ice chips, so that the hole is easy to block and jam. high risk drilling

[0007] 3. N-butyl acetate drilling fluid: It has been proved by engineering practice that although this type of drilling fluid can meet the density and viscosity conditions required for ice drilling, it is easy to damage the driller's body due to its high toxicity

[0008] 4. Drilling fluid with ISOPAR-K base fluid and hydrofluoroether HFE-7100 as thickener: the experimental results show that ISOPAR-K and HFE-7100 are easy to separate into two phases at -45°C, so they cannot be used in polar ice drilled

In addition, although HFE has low viscosity, low toxicity, no ignition point, and zero ozone depletion potential, it makes the global warming potential extremely high (from as low as hundreds to 15,000)

[0009] 5. Drilling fluid of bis-ether biological fatty acid ESTISOL240 and COASOL: Indoor and field experiments show that these products are not safe and environmentally friendly

Therefore, in order to achieve the best hoisting / lowering speed of the drilling tool, it is necessary to increase the gap between the drilling tool and the borehole wall, which will cause a large increase in the amount of ice debris, shortening the number of rounds, lower drilling speed and ice core damage. Issues such as lower adoption rate

[0010] To sum up, the currently commonly used drilling fluids will cause certain pollution to the polar air, snow, ice and other resources under the ice

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