SU1537685A1 - Method of producing drilling mud - Google Patents

Abstract

The invention relates to the drilling of wells, in particular to the preparation of drilling fluids on an input basis. The purpose of the invention is to reduce the permeability of the mud cake to water and increase its permeability to oil while improving the structural and mechanical parameters of the drilling fluid. Before introducing 30–60% of clay into the clay suspension, it is pre-moistened to 25–30% and treated with 1–2% hydrocarbon solution of an oil-soluble surfactant in an amount of 10–20% of the total solution. The resulting mixture is mixed with a clay slurry prepared from the remaining clay and treated with stabilizer reagents. As a hydrocarbon solution of surfactants using a solution emultal in oil in the following ratio, vol.%: Oil 99 - 98

emult 1 - 2. The drilling fluid prepared in this way has improved structural and mechanical properties and has a low filtration rate. Clay mud crust acquires a new property - to let the oil through and is an obstacle to water during its filtration. 1 hp f-ly, 4 tab.

Description

one

(21) 289391 / 23-03

(22) 05/27/87

(6) 01/23/90. Bul № 3 (70 Tatar State Research and Design Institute of the Oil Industry (72) N.I. Rylov and G.I. Zakharova (53) 622..1.3 (088.8)

(56) USSR Copyright Certificate If S77913, cl. From 09 K 7/02, 1981.

Melnikov I.I. and others. The use of oil emulsion drilling mud stabilized by emuls. - Gas industry, 198, № 10,

s.Y-15.

(5M METHOD FOR PREPARING DRILLING MACHINE

SOLUTIONS

(57) The invention relates to the drilling of wells, in particular to the preparation of drilling fluids on an input basis. The purpose of the invention is to reduce the permeability of a mudcake to water and increase its permeability to oil during

The invention relates to well drilling, in particular to the preparation of water-based drilling fluids.

The aim of the invention is to reduce the permeability of the mudcake to water and increase its permeability to oil while improving the structural and mechanical properties of the solution.

The method involves the preparation of drilling mud by mixing the clay suspension with a reagent stabilizer, for which part of the clay (30-60%)

simultaneous improvement of structural and mechanical parameters of the drilling fluid. Before introducing 30-60% of clay into the clay suspension, it is pre-moistened to 25-30% and treated with a 1-2% hydrocarbon solution of an oil-soluble surfactant in an amount of 10-20% of the total solution. The resulting mixture is mixed with a clay slurry prepared from the remaining clay and treated with stabilizer reagents. As a hydrocarbon solution of a surfactant, an emulsal solution in oil is used in the following ratio, vol.%: Oil, emulsion 1-2. The drilling fluid prepared in this way has improved structural and mechanical properties, has a low filtration rate. Clay mud crust acquires a new property - to let the oil through and is an obstacle to water during its filtration. 1 hp f-ly, A table.

pre-moistened with water to 25-30 ° C and treated with a hydrocarbon solution of an oil-soluble surfactant (surfactant) in an amount of 10-20% of the total solution, then the resulting mixture is mixed with a clay suspension prepared from the remaining clay and treated with reagents stabilizers, moreover, as a hydrocarbon solution of an oil-soluble surfactant, an emulstal solution in oil is used in the following ratio, vol.%:

(L

ate

oo

four

oh

00

ate

Oil 99-98

Emult 1-2

When moistening clay powder, water molecules adsorb on active surface centers, which are individual cells in the form of energy m.

Swarms of molecules arise around these centers at a certain humidity, isolated from each other by space free from water.

When treating moistened clay powder with a hydrocarbon surfactant solution, oil is adsorbed on the free surface to form a hydrophobic film, and the presence of surfactant prevents destruction of this film during subsequent mixing with the remaining clay suspension formed by stabilizer reagents. Thus, the clay powder becomes partially hydrophobized.

With further mixing, the treated clay powder is evenly distributed throughout the volume by dispersion. At the same time, the oil is firmly held by adsorption forces on the surface of the clay powder, which prevents its separation and floating on the surface of the solution, thereby increasing the stability of the resulting solution (daily sludge of the hydrocarbon is zero) and reducing its viscosity.

In addition, being in a bound state, the oil imparts the hydrophobic properties of the mudcake obtained from this solution, as a result of which the rate of filtration and transfer is sharply reduced.

Example. The process is carried out under laboratory conditions using a propeller agitator. The evaluation of the effectiveness of the solution preparation method is carried out by comparing the indicators of the structural and mechanical properties of the solutions prepared by various methods and the permeability of the mudcake of these solutions over water and oil.

Bentonite dry mud powder is used to prepare the solution. The solution is prepared with a density of 1150 kg / m.

.

The total amount of powder per liter of solution is 350 g.

Part clay powder in the amount of 87.5; 105, 175; 210; d that so10

five

76854

Corresponds to 25, 30, 50, 60 and 70 mAh, moistened with water up to $ 30 and treated with a hydrocarbon solution of surfactant composition, about; $:

oil 98

emultal 2

in the amount of 15% of the total solution. The amount of oil-soluble surfactant is due to experimental studies, which showed that to reduce the surface area 15 20

25 30 35

40

45

50

55

At the oil-water interface from 40 dyn-cm2 to a minimum, this ratio is optimal. A slurry is prepared from the remainder of the clay powder, treated with CMC reagents, Na4C03, according to a known recipe and technology. After that, both solutions are combined and subjected to dispersion, followed by measuring the indicators of the structural and mechanical properties of the solution.

I

In tab. 1 shows the data on the dependence of the bridge parameters of the solution on the amount of treated bentonite; in tab. 2 - data on the dependence of the parameters of the solution on the percentage of wetting of bentonite; in tab. 3 - dependence of solution parameters on the amount of hydrocarbon surfactant solution; in tab. C is the comparative data of the indicators of the structural-mechanical properties of the solution and the permeability of the mud cake, depending on the method of preparation.

The amount of clay powder treated, equal to 30-60 wt.% Of the total amount of clay powder, is optimal, since a decrease or increase in it leads to a deterioration of the structural and mechanical properties of the solution (Table 1, solution 1-5).

The optimum percentage of wetting of the clay powder is determined by comparing the indicators of the structural and mechanical properties of solutions in which the clay powder in the amount of 50% is moistened to 20.25.35 and 0% moisture.

From tab. 2 it can be seen that the pre-moistening of the clay powder to 25–30% is also optimal, since with a decrease in moisture content, the clay practically does not dmsr in the solution, and with an increase of 35 °

aggregative stability of the solution decreases, sludge of the hydrocarbon phase occurs, i.e. the solution becomes unstable.

In addition, the optimal addition of a hydrocarbon solution of the oil-soluble surfactant is checked. To do this, 50% of the clay powder is moistened to 30% and treated in the amount of 5,10,15,20 and 30% hydrocarbon solution of oil-soluble surfactant composition:

Oil 98

Emultal 2

Then it is mixed with the remaining clay suspension and the parameters are measured (Table 3).

From tab. 3 it can be seen that the amount of hydrocarbon surfactant in a volume of 10-20% is optimal, since when it decreases, the filtrate recoil increases, and with increasing viscosity and daily sludge, which indicates a decrease in the stability of the solution.

As can be seen from the table. And, the proposed solution in comparison with the known has better structural and mechanical properties, while having a higher permeability

oilcake peel and lower water permeability.

Claims (2)

Invention Formula The method of preparation of the drilling fluid, including the preparation of a clay suspension in water and the introduction into the obtained clay suspension of the stabilizer reagent and hydrocarbon, characterized in that, in order to reduce the permeability of the mud cake to water and increase its permeability to oil while simultaneously improving the structural and mechanical parameters of the drilling mud, before preparing the clay suspension, clay moistened with water to a moisture content of 25–30% and treated with a 1-2% solution of an oil-soluble surfactant in less than 1%; the solution of the oil-soluble surfactant used in an amount of 10–20% of the total volume of drilling mud. 2. Method pop.1, characterized by the fact that emultal is used as an oil-soluble surfactant. Solution The composition of the solution Solution parameters T b g and h a 3 The well-known 4.0-8.0 3-1U 5-180 3-Yu OtO, 5 The proposed 5.0-5.0 1.2-1.4 2.4-2.5 2-2.8 7-Yu Table k 8-10 1.5-2.5