Recycled solidfree micro-foam drilling fluid or completion fluid

Abstract

The invention is a recycled solidfree micro-foam drilling fluid or a completion fluid, which comprises the following components in parts by weight: 1. 2-3 parts of recycled solidfree micro-foam composite treatment agent SD-LNA; 2. 0.5-1 part of low-density solidfree tackifier SD-LNV; 3 0.5-1 part of low-density modifier SD-LFD; 4. 0.5-1 part of low-density foam stabilizer SD-LFS; 5. 0.5-1 of low-density flow type modifier SD-LFR; and 6. 100 parts of water. According to a normal preparation method, the above substances are added into water successively, mixed and stirred evenly under normal temperature and normal pressure. The invention has the advantages of low density, high viscosity, small low fluid loss, good lubricating property, strong landwaste suspension property, easy maintenance,fine cleaning capability of wells, fine inhibitory capability on clay and shale, no micro-foam convergence, recycled use and the like, can be widely applied in engineering such as petroleum, geologicdrilling and the like, is particularly applicable to construction technology of well drilling and well completion of low-pressure reservoir and exhausted reservoir.

Description

1. Technical field [0001] The invention relates to a drilling fluid and a well completion fluid, in particular to a recyclable solid-free microfoam drilling fluid or well completion fluid. 2. Background technology [0002] With the continuous expansion of oil and gas exploration and development areas, oil drilling has gradually developed from oil-rich areas to low-pressure, low-permeability formations and depleted formations. During the exploration and development of these oil formations, recyclable microfoam drilling fluid technology is often used. "Geology and Exploration" magazine, Volume 44, Issue 5, published an article entitled "Application of Recyclable Microfoam Mud in In-situ Sandstone Uranium Ore" in September 2008, introducing a microfoam drilling fluid, Its formula is: 4%-5% pre-hydrated bentonite slurry + 0.1% sodium hydroxide + 0.2%-0.3% foam stabilizer + 0.2%-0.3% medium viscosity flocculent cellulose CMC + 0.1%-0.3% foam agent. The disadvantages or deficien...

AI Technical Summary

Problems solved by technology

The disadvantages or deficiencies of the above technology are: ①The system contains bentonite, which requires pre-hydration of bentonite slurry, which is complicated to prepare and takes a long time to wait; ②The formed foam structure is loose and has poor stability; ③The high solid phase in the foam system is not conducive to underground Maintain low density under pressure, used in low porosity and low permeability reservoirs and in mudstone formations where hydration expansion is easy to occur, blocking the pores of gas layers, causing great damage to the reservoir and affecting oil recovery