A kind of composite brine drilling fluid

Abstract

The invention discloses a compound brine drilling fluid which comprises the following components in parts by weight: 100 parts of water, 0.12-0.17 parts of sodium hydroxide, 0.15-0.25 parts of polyanionic cellulose, 0- 0.3 parts of carboxymethyl cellulose, 2-5 parts of calcium carbonate, 0.8-1.2 parts of sulfonated tannin, 0.8-1.3 parts of graphite powder, 0-1 part of filtrate reducer A, 0.8-1.2 parts of filtrate reducer B, 2-10 parts of sodium formate, 3-15 parts of sodium chloride and 1.8-2.5 parts of potassium chloride. The composite brine drilling fluid disclosed by the invention has good inhibition effect on water-sensitive minerals in reservoirs and low harm to the permeability of reservoirs, is free of clay phase and low in the content of solid phase and hardly damages stratum. The composite brine drilling fluid has the advantages of good rheology, strong inhibition and lower cost; the site preparation process is simple, operation and maintenance are convenient and the composite brine drilling fluid can be effectively applied to protective drilling operations of low-porosity, low-pressure and low-permeability reservoirs.

Description

technical field

[0001] The invention belongs to the technical field of drilling fluids, in particular to a composite brine drilling fluid. Background technique

[0002] Drilling fluid is the circulating flushing medium used in the hole during the drilling process. The main functions of drilling fluid are: cleaning the bottom of the well, carrying cuttings; cooling and lubricating the drill bit and drill string; balancing the side pressure of the rock on the well wall, forming a filter cake on the well wall, sealing and stabilizing the well wall; controlling the formation pressure; suspending cuttings and weighting agent; effective transmission of hydraulic efficiency; hydraulic breaking of rocks, etc. Drilling fluid can be divided into water-based drilling fluid, oil-based drilling fluid, gas-based drilling fluid, etc. according to the dispersion medium (continuous phase). Among them, the most widely used is water-based drilling fluid. Water-based drilling fluid is a sol-...

Examples

Embodiment 1

[0014] The composite brine drilling fluid of the present embodiment comprises the following components by weight: 100 g of water, 0.15 g of sodium hydroxide, 0.2 g of high-viscosity polyanionic cellulose, 0.3 g of low-viscosity carboxymethyl cellulose, 1 g of sulfonated phenolic resin, Sulfonated tannin extract 1g, superfine calcium carbonate 5g, graphite powder 1g, sodium formate 10g, sodium chloride 15g, potassium chloride 2g.

[0015] The preparation method of the composite brine drilling fluid in this embodiment is as follows: Weigh water, add sodium hydroxide, high-viscosity polyanionic cellulose, low-viscosity carboxymethyl cellulose, sulfonated phenolic resin, and sulfonated tannin extract successively under stirring conditions , superfine calcium carbonate, graphite powder, after mixing evenly, slowly add sodium formate, sodium chloride, potassium chloride under high-speed stirring, after fully stirring evenly, let stand at room temperature for 24h, that is.

[0016] T...

Embodiment 2

[0029] The composite brine drilling fluid of this embodiment comprises the following components by weight: 100 g of water, 0.15 g of sodium hydroxide, 0.2 g of high-viscosity polyanionic cellulose, 1 g of sulfonated phenolic resin, 1 g of sulfonated tannin extract, and ultrafine calcium carbonate 2g, graphite powder 1g, salt-resistant polymer fluid loss reducer (GMP-1, commercially available, purchased from Xinjiang Korla Wanshunda Petroleum Technology Co., Ltd.) 1g, sodium formate 2g, sodium chloride 3g, potassium chloride 2g.

[0030] The preparation method of the composite brine drilling fluid of this embodiment is as follows: Weigh water, add sodium hydroxide, high-viscosity polyanionic cellulose, sulfonated phenolic resin, sulfonated tannin extract, ultrafine calcium carbonate, graphite powder in sequence under stirring conditions , Salt-resistant polymer fluid loss reducer (GMP-1), after mixing evenly, slowly add sodium formate, sodium chloride, potassium chloride under h...

Embodiment 3

[0045] The composite brine drilling fluid of this embodiment comprises the following components by weight: 100 g of water, 0.12 g of sodium hydroxide, 0.15 g of high-viscosity polyanionic cellulose, 0.15 g of low-viscosity carboxymethyl cellulose, and 0.8 g of sulfonated phenolic resin , sulfonated tannin extract 1.2g, superfine calcium carbonate 3g, graphite powder 0.8g, salt-resistant polymer fluid loss reducer (GMP-1, commercially available, purchased from Xinjiang Korla Wanshunda Petroleum Technology Co., Ltd.) 0.5g , sodium formate 5g, sodium chloride 5g, potassium chloride 1.8g.

[0046] The preparation method of the composite brine drilling fluid in this embodiment is as follows: Weigh water, add sodium hydroxide, high-viscosity polyanionic cellulose, low-viscosity carboxymethyl cellulose, sulfonated phenolic resin, and sulfonated tannin extract successively under stirring conditions , superfine calcium carbonate, graphite powder, salt-resistant polymer fluid loss reduc...

technical field

[0001] The invention belongs to the technical field of drilling fluids, in particular to a composite brine drilling fluid. Background technique

[0002] Drilling fluid is the circulating flushing medium used in the hole during the drilling process. The main functions of drilling fluid are: cleaning the bottom of the well, carrying cuttings; cooling and lubricating the drill bit and drill string; balancing the side pressure of the rock on the well wall, forming a filter cake on the well wall, sealing and stabilizing the well wall; controlling the formation pressure; suspending cuttings and weighting agent; effective transmission of hydraulic efficiency; hydraulic breaking of rocks, etc. Drilling fluid can be divided into water-based drilling fluid, oil-based drilling fluid, gas-based drilling fluid, etc. according to the dispersion medium (continuous phase). Among them, the most widely used is water-based drilling fluid. Water-based drilling fluid is a sol-...

Examples

Embodiment 1

[0014] The composite brine drilling fluid of the present embodiment comprises the following components by weight: 100 g of water, 0.15 g of sodium hydroxide, 0.2 g of high-viscosity polyanionic cellulose, 0.3 g of low-viscosity carboxymethyl cellulose, 1 g of sulfonated phenolic resin, Sulfonated tannin extract 1g, superfine calcium carbonate 5g, graphite powder 1g, sodium formate 10g, sodium chloride 15g, potassium chloride 2g.

[0015] The preparation method of the composite brine drilling fluid in this embodiment is as follows: Weigh water, add sodium hydroxide, high-viscosity polyanionic cellulose, low-viscosity carboxymethyl cellulose, sulfonated phenolic resin, and sulfonated tannin extract successively under stirring conditions , superfine calcium carbonate, graphite powder, after mixing evenly, slowly add sodium formate, sodium chloride, potassium chloride under high-speed stirring, after fully stirring evenly, let stand at room temperature for 24h, that is.

[0016] T...

Embodiment 2

[0029] The composite brine drilling fluid of this embodiment comprises the following components by weight: 100 g of water, 0.15 g of sodium hydroxide, 0.2 g of high-viscosity polyanionic cellulose, 1 g of sulfonated phenolic resin, 1 g of sulfonated tannin extract, and ultrafine calcium carbonate 2g, graphite powder 1g, salt-resistant polymer fluid loss reducer (GMP-1, commercially available, purchased from Xinjiang Korla Wanshunda Petroleum Technology Co., Ltd.) 1g, sodium formate 2g, sodium chloride 3g, potassium chloride 2g.

[0030] The preparation method of the composite brine drilling fluid of this embodiment is as follows: Weigh water, add sodium hydroxide, high-viscosity polyanionic cellulose, sulfonated phenolic resin, sulfonated tannin extract, ultrafine calcium carbonate, graphite powder in sequence under stirring conditions , Salt-resistant polymer fluid loss reducer (GMP-1), after mixing evenly, slowly add sodium formate, sodium chloride, potassium chloride under h...

Embodiment 3

[0045] The composite brine drilling fluid of this embodiment comprises the following components by weight: 100 g of water, 0.12 g of sodium hydroxide, 0.15 g of high-viscosity polyanionic cellulose, 0.15 g of low-viscosity carboxymethyl cellulose, and 0.8 g of sulfonated phenolic resin , sulfonated tannin extract 1.2g, superfine calcium carbonate 3g, graphite powder 0.8g, salt-resistant polymer fluid loss reducer (GMP-1, commercially available, purchased from Xinjiang Korla Wanshunda Petroleum Technology Co., Ltd.) 0.5g , sodium formate 5g, sodium chloride 5g, potassium chloride 1.8g.

[0046] The preparation method of the composite brine drilling fluid in this embodiment is as follows: Weigh water, add sodium hydroxide, high-viscosity polyanionic cellulose, low-viscosity carboxymethyl cellulose, sulfonated phenolic resin, and sulfonated tannin extract successively under stirring conditions , superfine calcium carbonate, graphite powder, salt-resistant polymer fluid loss reduc...

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