Low solid phase and micro-foam drilling fluid or completion fluid capable of being used circularly

Abstract

The invention discloses a low solid phase and micro-foam drilling fluid or completion fluid capable of being used circularly, comprising the following components in portions by weight: 3-4 portions ofmicro-foam and low-solid phase composite treating agent SD-LGA capable of being used circularly, 0.5-1 portion of low-density and low-solid phase tackifier SD-LGV, 0.5-1 portion of low-density regulator SD-LFD, 0.5-1 portion of low-density foam stabilizer SD-LFS, 0.5-1 portion of low-density flowing type regulator SD-LFR and 100 portions of clear water. The preparation method comprises the following steps: sequentially adding the components into the clear water in a conventional preparation method according to the weight content of each component at normal temperature and normal pressure, andthen, uniformly mixing and stirring the components for use. The drilling fluid or completion fluid has the advantages of low solid phase, low density, high foam stability, high structural strength, high fluid phase viscosity, high flexibility, high lubricity, very low toxicity, easy biodegradation, circular use, little influence on environment, little harm to a storage layer, high permeability recovery value, good effect on protection of an oil-gas layer and the like, and is widely applied to a drilling engineering technology of petroleum and geology.

Description

1. Technical field [0001] The invention relates to a drilling fluid and a well completion fluid, in particular to a recyclable low solid phase microfoam drilling fluid or well completion fluid. 2. Background technology [0002] In oil and gas exploration in low pressure, low permeability and depleted formations, recyclable microfoam drilling fluid technology is often used. Chinese Patent No. 20041001323.7 titled "Application and Preparation Method of Surplus Activated Sludge Protein as Foam Drilling Fluid" discloses a kind of microfoam drilling fluid, its formula and content are, parts by weight: bentonite 5, tackifier 0.1 , Stabilizer 0.2, Foaming Agent 0.5; Viscosifier is hydroxymethyl cellulose; Stabilizer is polyacrylamide. The disadvantages or deficiencies of this technology are: ① the content of bentonite is high, and the bentonite slurry needs to be pre-hydrated, and the preparation is long and complicated; Unstable, poor foam stability, difficult to control the den...

AI Technical Summary

Problems solved by technology

The disadvantages or deficiencies of this technology are: ①The content of bentonite is high, and the bentonite slurry needs to be pre-hydrated. The preparation process is long and the preparation procedure is complicated; Unstable, poor foam stability, difficult to control the density, increasing the difficulty of maintenance and treatment; ③Used in low-porosity and low-permeability reservoirs and in mudstone formations, it is easy to cause hydration expansion, block the pores of the gas layer, and cause damage to the reservoir Great damage, affecting oil recovery