Oil-based drilling fluid

Abstract

The invention discloses oil-based drilling fluid and belongs to the technical field of chemistry of the oil-gas field. The oil-based drilling fluid comprises the following components in percentage by weight: 1%-3% of wetting agent, 50-80% of base oil, 5%-10% of CaCl2 salt water, 2%-5% of emulsifying agent, 3%-6% of fluid loss agent, 0.5%-3% of calcium hydroxide, 0.3%-2% of gelling agent, 0.5%-3% of viscosity increasing agent and the balance of weighting material, wherein the wetting agent comprises the following components in percentage by weight: 60% of vegetable pin tar and 40% of vegetable oleic acid. The oil-based drilling fluid has the advantages that the components of the wetting agent are low in cost and are not limited by the source; the condensation of the weighing material can be effectively avoided, the suspending stability of the weighing material in the drilling fluid system is improved and the requirement of the drilling construction of the non-conventional oil-gas reservoir for the high-density oil-based drilling fluid is met.

Description

technical field [0001] The invention belongs to the technical field of oil and gas field chemistry, and relates to an oil-based drilling fluid, in particular to a high-density oil-based drilling fluid formulated with a wetting agent composed of vegetable pine tar and vegetable oleic acid. Background technique [0002] Drilling fluid, also known as drilling flushing fluid, is a circulating flushing medium used in the drilling process. Drilling fluid mainly completes the tasks of suspension, pressure control, formation stability, buoyancy, lubrication and cooling during the drilling process. Drilling fluid has the functions of cleaning the bottom of the well and carrying cuttings; cooling and lubricating the drill bit and drill string; balancing the side pressure of the well wall rock, sealing and stabilizing the well wall; balancing the formation pressure; reducing the sedimentation velocity of cuttings; cuttings; effectively transmit hydraulic power; bear part of the gravit...

AI Technical Summary

Problems solved by technology

[0006] It should be noted that the wetting effect of foreign wetting agent products is good, especially in high-density oil-based drilling fluids, which have little impact on the rheology of the system and will not cause thickening of high-density drilling fluids, but the price is high and the source limited

Domestic products have unsatisfactory wetting effects under high-density conditions, and heavy materials precipitate due to poor wetting, resulting in difficulty in stabilizing the density and often greatly increasing the viscosity of the system, resulting in too thick drilling fluid, seriously affecting the rheology of the system, and affecting subsequent drilling operations. It brings a series of problems, such as poor tripping, drilling fluid sticking to drill pipe, etc., and domestic products have insufficient temperature resistance

Images