SU1654541A1 - Buffer liquid - Google Patents

Abstract

The invention relates to the drilling of oil and gas wells. The goal is to increase the displacing and cleaning ability while at the same time eliminating coagulation in the zone of contact with the drilling sponge. The buffer liquid contains a mineral salt and an alkaline additive, in which it contains the bottom residue of glycerol production in a quantity of from 10 to 20% of the total mass. The use of this buffer fluid in well cementing, especially with small annular gaps, improves the quality of well cementing, prevents a number of complications with severe, ag. When preparing a buffer fluid, the required amount of water is drawn into the measuring tank of the cementing unit. with which the reagent amount of polyglycerol is dissolved, 2 tab. WITH

Description

The invention relates to the drilling of oil and gas wells, in particular to buffer fluids used in casing cementing.

The aim of the invention is to increase the displacing and cleaning capacity of the buffer fluid while at the same time eliminating coagulation in the zone of contact with the drilling and tampon mortar.

The water-based buffer liquid, containing an alkaline additive and a mineral salt, contains a 10-20% aqueous solution of the bottom residue of glycerin production, containing, in wt%:

Polyglyceric28-34

Caustic soda4-5

Sodium carbonate 2-3

Sodium chloride6-8

WaterEverything

In tab. Figures 1 and 2 show the nature of the compatibility of buffer fluids with drilling fluids and cement mortars, respectively.

The use of a buffer fluid in well cementing, especially with small annular gaps, will improve the quality of well cementing, prevent a number of complications with serious consequences. This is explained by the fact. that, due to the low rheological characteristics of the buffer fluid, its movement in the annular spaces is maintained under turbulent regime. Due to the turbulent flow of the buffer solution, the cleaning efficiency of the annular space from the clay and mudcake particles increases, resulting in improved adhesion of the cement stone to the rock and metal of the casing columns. Indicators of buffer fluid.

/ 9 1020-1050 kg / m3 (if sea water is p -1700-1090 kg / m3). pH 12.5. conditional viscosity 15 s.

About SP

N ate

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Buffer preparation technology is very simple, before cementing the necessary amount of water into the measuring tank of the cementing unit CA-320 M in the measuring tank in which the reagent amount of polyglycerol is dissolved (based on the given concentration and volume of the buffer liquid). For example, to prepare 1m of a buffer liquid of 10% concentration, 900 liters of water and 100 liters of waste glycerin production are needed. The total cooking time is 10-20 minutes.

The widespread use of buffer fluid in well cementing will increase its quality and reduce the number of defects.

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Claims (1)

Invention Formula A water-based buffer fluid containing a mineral salt and an alkaline additive, characterized in that, in order to increase the displacing and cleaning ability while at the same time excluding coagulation in the zone of contact with the drilling and cement slurry, it contains VAT residue of glycerin production in the amount of 10-20% of the total mass. Note. Drilling muds have the following composition, May%: 1 - clay 9.0; Seragel 2.5: NaOH 1.5; MAPSO 1.0; MgCh 1,2; CaCIa 0.3; NaCl 21; KSSB 3,5; water else; 2 - clay 9.0; # 2CO3 0.5; CSR 8; water else; 3 - clay 9.0; Sergegel 1,5; NaOH 2; water the rest. Table 1 Table 2