Anti-collapse circulative micro-foam drilling fluid or well completion fluid

Abstract

The invention discloses an anti-collapse circulating microfoam drilling fluid or completion fluid, which consists of (A) base slurry: bentonite 2-4.5 or 6-10, soda ash 0.2-0.3 water 100 parts by weight. (B) Additives: ① Anti-slump agent 2-5, ② Cementing agent 3-5, ③ Viscosifier 0.5-3, ④ Fluid loss reducer 1-3, ⑤ Foaming agent 0.5-5, foam stabilizer 0.5- 2.5, flow regulator 0.5-2.5. The invention has strong anti-slump function and strong adaptability, can be used as both drilling fluid and completion fluid, can be applied to low-pressure carbonate formations, and low-pressure, low-permeability mudstone formations and rock formations It is mainly used in drilling and completion of low-pressure, low-permeability and easy-collapse formations.

Description

1. Technical field [0001] The invention relates to drilling and well completion fluids, in particular to an anti-collapse circulating microfoam drilling fluid or well completion fluid. 2. Background technology [0002] The existing foam 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", the 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 shortcoming is that it can only be used in conventional hard formations, and hydration expansion is very easy to occur in mudstone formations, blocking steam layer pores, causing great damage to the reservoir; foam stability is poor, can not improve the anti-collapse ability of drilling fluid; (2) Chinese Patent No. 20041001323.7 is titled "Application and Preparation Method of Residual Activated Sludge Protein as Foam Drilling Fluid" ", the formula of this method is parts by weig...

AI Technical Summary

Problems solved by technology

[0002] The existing foam 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", the 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 shortcoming is that it can only be used in conventional hard formations, and hydration expansion is very easy to occur in mudstone formations, blocking steam layer pores, causing great damage to the reservoir; foam stability is poor, can not improve the anti-collapse ability of drilling fluid; (2) Chinese Patent No. 20041001323.7 is titled "Application and Preparation Method of Residual Activated Sludge Protein as Foam Drilling Fluid" ", the formula of this method is parts by weight: bentonite 5, tackifier 0.1, stabilizer 0.2, foaming agent 0.5; tackifier is hydroxymethyl cellulose; stabilizer is polyacrylamide; in a word, above-mentioned technical function is single , no anti-collapse effect, poor adaptability, can only be used in hard formations, and can only be adapted to drilling in limestone formations, the effect is poor, and the use cost is high. Can not be reduced, aggravating downhole complexity