Synthetic base drilling fluid

Abstract

The invention discloses synthetic base drilling fluid, which comprises ingredients: base fluid, alkalinity regulating agents, weighting agent and water, wherein emulsion which has the PH value being 8.5 to 10 and the specific weight being 1.2 to 2.0g / cm<3> and is formed by uniformly mixing the ingredients is the drilling fluid, and the base fluid comprises ingredients: limonene, bipentene, butylcellosolve, alkyl polyglucoside, alcohol ether carboxylate, white oil and simethicone. The drilling fluid has the advantages of both ether base type drilling fluid and alpha-olefin type drilling fluid, the influence on the viscosity of the drilling fluid caused by the temperature change is little, the application range is wide, the adopted raw materials hardly contain dutrex, in addition, the price is low, the production cost is low, the biological degradability is good, the environmental-friendly effect is realized, the drilling fluid can adapt to wide acid-base conditions, and excellent surface activity, lubricating performance and chemical stability are realized.

Description

technical field [0001] The present invention relates to a synthetic base drilling fluid. Background technique [0002] Synthetic-based drilling fluids emerged when water-based drilling fluids could not meet the performance requirements of downhole complex conditions, and oil-based drilling fluids could not meet environmental protection requirements. As soon as the synthetic base drilling fluid appeared, it showed a good development prospect and achieved remarkable environmental and economic benefits. [0003] Base fluid is the main component of drilling fluid, and its performance indicators determine most of the performance indicators of drilling fluid, such as flash point, viscosity and freezing point. At present, the base fluids of synthetic-based drilling fluids can be divided into three types: ester-based, ether-based, and α-olefin. Made of similar components, so the performance is single. Drilling fluids made of ester-based and ether-based base fluids have the follow...

AI Technical Summary

Problems solved by technology

At present, the base fluids of synthetic-based drilling fluids can be divided into three types: ester-based, ether-based, and α-olefin. Made of similar components, so the performance is single

Drilling fluids made of ester-based and ether-based base fluids have the following main disadvantages: First, the active carboxyl groups in the base fluid molecules are easily damaged by alkaline or acidic substances to generate alcohols and carboxylic acids. Therefore, during drilling, The intrusion of acid gas will lead to ester hydrolysis, which will affect the stability of drilling fluid. Second, when drilling offshore wells, the drilling fluid may drop to around 4°C due to the cooling effect of seawater after the pump is stopped. At such a low temperature, the drilling fluid Can become too thick, causing pump pressure to rise, causing downhole complications such as formation fractures and wellbore instability

Drilling fluids made of α-olefin base fluids have lower viscosity than ester-based and ether-based fluids, thus solving the problem of high low-temperature viscosity of drilling fluids, but the ensuing problem is that the viscosity of drilling fluids is low, making drilling Fluid rheological properties are significantly affected by temperature and pressure, leading to problems such as wellbore purification, barite settlement, and high cycle pressure loss

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