High temperature resistant circulating micro-foam drilling fluid or completion fluid

Abstract

The invention discloses a high-temperature-resistant recyclable micro-foam drilling fluid or well-completion fluid, which is composed of: (A) base slurry: 1-2 bentonite, 3-5 salt-resistant clay, 0.2-0.3 soda ash, and 100 parts by weight ;(B) Additives: ①High temperature inhibitor 3-5, ②High temperature viscosifier 2-5, ③High temperature fluid loss reducer 3-6, ④High temperature salt resistance, viscosity raising fluid loss reducer 1-3, ⑤Flow type Regulator 1-3, ⑥ high temperature foaming agent 2-5, ⑦ high temperature foam stabilizer 1-2.5. The invention has high temperature resistance, good carrying and suspension ability in low pressure deep wells, can be used for deep well exploration and development, has strong adaptability, can be used as drilling fluid and well completion fluid, and can be used in high temperature deep wells and low pressure Carbonate formations can also be used in high-temperature, low-pressure, low-permeability mudstone formations, mudstone shale reservoirs and salt-bearing formations. They have the ability to inhibit hydration expansion of mudstone and have a good effect of protecting oil and gas layers. They are mainly used in low-pressure, low-permeability Formation drilling and well completion construction process.

Description

1. Technical field [0001] The invention relates to drilling and well completion fluids, in particular to a high-temperature-resistant circulating microfoam drilling fluid or well completion fluid. 2. Background technology [0002] The existing microfoam drilling fluid technology used in oil drilling has (1) Chinese Patent No. 200410021014.8 titled "A Microfoam Foaming Agent and its Drilling Fluid System Formula", and its formula is: 5% base slurry+0.3% MF+0.03%SF+2%SMP-II+0.05%80A-51+0.2%XC+1%SPNH, its shortcoming or deficiency is that it can only be used in shallow wells and hard formations, and the foam has poor high temperature stability and cannot be used at high temperatures; (2 ) Chinese Patent No. 200410013232.7 titled "Application and Preparation Method of Surplus Activated Sludge Protein as Foam Drilling Fluid", its formula is parts by weight: bentonite 5, tackifier 0.1, stabilizer 0.2, foaming agent 0.5; The agent is hydroxymethyl cellulose; the stabilizer is poly...

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Problems solved by technology

[0002] The existing microfoam drilling fluid technology used in oil drilling has (1) Chinese Patent No. 200410021014.8 titled "A Microfoam Foaming Agent and its Drilling Fluid System Formula", and its formula is: 5% base slurry+0.3% MF+0.03%SF+2%SMP-II+0.05%80A-51+0.2%XC+1%SPNH, its shortcoming or deficiency is that it can only be used in shallow wells and hard formations, and the foam has poor high temperature stability and cannot be used at high temperatures; (2 ) Chinese Patent No. 200410013232.7 titled "Application and Preparation Method of Surplus Activated Sludge Protein as Foam Drilling Fluid", its formula is parts by weight: bentonite 5, tackifier 0.1, stabilizer 0.2, foaming agent 0.5; The agent is hydroxymethyl cellulose; the stabilizer is polyacrylamide; the above-mentioned foam technology has poor high-temperature stability and can only be used in low-temperature shallow wells, and can only be adapted to drilling in limestone formations. The effect is poor, and the use cost is high. During construction, the foam stability is poor, and the density cannot be reduced. When applied in high-temperature deep well reservoirs, it will cause serious pollution to the reservoir

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