SU1321740A1 - Composition for exposing production formation - Google Patents

Abstract

The invention relates to the field of the oil industry and is intended to segregate the formation from the wellbore during current and capital repairs and may be. used in drilling and development of wells. The purpose of the invention is to increase the efficiency of the reservoir through the restoration of its initial permeability. The composition contains the following components at their ratio (wt.%): Carboxymethylcellulose (KSH) O, 5-5, o; starch - 0.1-3.0; water - the rest. The composition is prepared as follows. B, the container is filled with water, CMC and starch are added. Make up the volume with water to a certain value and mix until all the starch and the starch are completely dissolved. At the same time, CMC forms with the starch on the surface of particles and in the pores a dense, thin impermeable polymer-starch crust, which allows to reduce watering and clogging of the well bottom zone. The composition that has penetrated the pores of the formation is easily removed from it when the well is developed. The presence of starch - small in composition makes it possible to destroy the polymer crust of the CMC. 1 tab. with

Description

113

The invention relates to the oil industry, in particular, to the separation of the reservoir and the wellbore during current and major repairs and can be used in drilling and development of wells.

The aim of the invention is to increase the efficiency of the opening of the reservoir due to the restoration of its initial permeability.

To prepare the composition, water is collected in a container, carboxymethylcellulose (CMC) and starch are added, the volume is adjusted to a certain value with water and mixed until the CMC and starch are completely dissolved.

Example 1: 500 g of water are collected in a container, placed under a mixer, 5-50 g of CMC, 1-30 g of starch are added, the volume is adjusted to 1000 g with water and stirred until complete dissolution of CMC and starch.

Example 2 Into a container I take 500 g of water, put under a mixer, add 5-50 g of CMC, 1-30 g of starch, bring the volume to 1000 g with water and mix until complete dissolution of CMC and starch. To the prepared solution, 0.1-5 g of OP-10 or disolvan, or excellent are added and mixed until the surface-active substances are evenly distributed in the solution.

Example 3. 500 g of water are poured into the container, placed under a mixer, 5-50 g of CMC, 1-30 g of starch are added, the volume is made up with water to gcc and mixed until CMC and starch are completely dissolved. 30-700 g of calcium carbonate is added to the prepared solution and stirred until a uniform suspension is formed.

Calcium carbonate in the amount of 3.0 to 7.0% of the volume of the drilling mud can be added for the purpose of temporary grinding of highly permeable MI and fractured rocks.

Carboxymethylcellulose (SM) forms with the starch on the surface of the particles and in the pores a dense, thin impermeable polymer-starch crust that allows reducing the watering and clogging of the bottom-hole zone of the well. The composition that has penetrated the pores of the formation is easily removed from the formation during well completion.

The main purpose of starch in this composition is to destroy

2

CMC polymer peel by decomposing starch in the peel. When decomposed, starch forms voids in the crust, as a result of which the resistance to movement of formation fluid is reduced, and the latter displaces carboxymethylcellulose from the pores of the rocks.

The decomposition of starch leads to the rapid dissolution of the polymer peel of CMC.

The study to assess the recoverability of the permeability of the reservoir was carried out according to a standard method using cores of the following compositions:

core 1. 60% aleurolite and 40% argillite. Porosity 12%, permeability 175 ppm;

core 2. 71% sandstone and 29 mudstone. -Porosity of 14.5%, permeability 211 u;

core 3. 62% limestone and 38% marl. The cracks are vertical and horizontal. Porosity is 6.9%, permeability is 74 md.

To determine the permeability, a cylinder with a diameter of 30 mm and a height of 30 mm is made from natural core. To release the rock from the water, the cylinder is placed in a drying

The cabinet is heated to 105 ° C and held there for 3-4 hours, then the sample is cooled and placed in the core holder of the unit.

Having secured the sample in the core holder,

check the tightness of its seal. After checking the tightness of its fixation, they proceed to the determination of permeability, increasing the pressure in the hydro-pressing system to 500 atm, and

gas to 200 atm.

When the pressure of the incoming jet reaches a predetermined value, the gas flow rate is determined. Convinced of the constancy of this flow, determine its

the value and the usual way to calculate the coefficient of permeability.

First, the permeability of the core sample is determined, then the proposed solution is pumped through it, the core is left in the solution for 10 days and the permeability of the sample is again determined at a pressure of 200 atm and a temperature of 70 ° C.

The results are presented in the table.

Claims (1)

Invention Formula Composition for opening the reservoir containing carboxymethyl313217404 cellulose and water, differently contain starch at the next with the fact that, in order to improve the components ratio, wt,%: to reveal the productive Carbox Methyl Cellcoleshoke 0.5-5.0 of the reservoir due to the restoration of its is Starch. 0.1-3.0. permeability, it is also an additional water. 0.5% CMC 85/500 + 99.5% water 3.35 CMC 85/500 + + 96.75% water 6% CMC 85/500 + + 94% water 0.4% CMC 85/500 + + 1.55% starch MK-1 + 98,0,5% water 0.5% CMC 85/500 + + 1.55% starch MK-1 + 97.95% water 3.25 CMC 85/500 + + 1.55% starch MK-1 + 95.20% water 5% CMC 85/500 + + 1.55% starch MK-1 + 93.45% birth 6% CMC 85./500 + -t- 1.55 starch MK-1 + 92.45 water 63 3.25% CMC 85/500 + + 0.05% starch MK-1 + 96.7% water 3.25% CMC 85/500 + + 0.1% starch MK-1 + 96.65% water 3.25% CMC 85/500 + 4- 3% starch MK-1 + 93.75% water O / O 9 0.31 0.19 0.39 O / O 3, 0 0.34 0.21 0.42 O / O 0.5 0.41 0.29 0.51 0.36 0.78 0.91 0.88 O / O 0.5 0.72 0.58 0.78 O / O 3.0 0.32 0.20 0.40 O / O 3.0 0.50 0.32 0.53 O / O 2 0.74 0.52 0.91 3.25% CMC 85/500 + starch MK-1 + + 91.75% water 61 0.4% CMC 85/500 + + 1.55% unmodified starch + 98.05% water 27 0.5% CMC 85/500 + + 1.55% unmodified starch + 97.95% water 32 15 3.25% CMC 85/500 + + 1.55% unmodified starch + + 95.20% water 38 5% CMC 85/500 + + 1.55% unmodified starch + 93.45% water 44 6% CMC 85/500 + + 1.55% unmodified starch + 92.45% water 49 18 3.25% CMC 85/500 + 4- 0.05% unmodified starch + + 96.7% water 48 3.25% CMC 85/500 + + 0.1% unmodified starch + 96.65 water 20 20 3.25% CMC 85/500 + + 3% unmodified starch + + 93.75% water 46 Table continuation O / O 0.5 0.78 0.54 0.93 O / O 4 0.52 0.30 0.46 O / O 2.5 0.85 0.66 0.91 O / O 0.5 0.93 0.72 0.94 O / O -0.5 0.86 0.64 0.91 O / O 0.5 0.85 0.64 0.91 O / O 2.5 0.35 0.21 0.39 O / O 2.5 0.37 0.25 0.45 O / O 1.5 0.86 0.57 0.95 The components of the composition and their number 3.25% CMC 85/500 + + 5% unmodified starch + + 91.75% water 0.4% KWH 85/500 + + 1.55% phosphate-modified starch + 98.05% water 47 37 0.5% CMC 85/500 + + 1.55% starch modified with phosphates + 97.95% water41 3.25% CMC 85/500 + + 1.55% phosphate-modified starch - (- 95.20% water50 5% CMC 85/500 + + 1.55% phosphate-modified starch + 93.45% water 55 6% CMC 85/500 + + 1.55% phosphate-modified starch + 92.45% water 61 3.25% CMC 85/500 + + 0.05% starch modified with phosphates + 96.7% water 58 3.25% CMC 85/500 + + 0.1% phosphate-modified starch, 96.65% water 28 O / O 0.5 0.91 0.59 0.99 O / O 5 0.40 0.21 0.38 О / .О 0.71 0.54 0.77 O / O 0.5 0.76 0.63 0.98 O / O 0.5 0.73 0.55 0.90 O / O 0.5 0.71 0.56 0.78 O / O. 2.5 0.34 0.18 0.38 O / O 3.0 0.49 0.31 0.52 3.25% CMC 85/500 + -t- 3% starch modified with phosphates + 93.75% water 55 3.25% CMC 85/500 + + 5% starch, modified by phosphates + 91.75% water 68 No 6 + 2.0% calcium carbonate 52 No. b + 3.0% calcium carbonate No. 6 + 36.5% calcium carbonate No. 6 + 70% calcium carbonate No. 6 + 80% calcium carbonate 52 64 97 118 No. 15 + 2.0% calcium carbonate No. 15 + 3.0% calcium carbonate No. 15 + 36.5% calcium carbonate No. 15 + 70% calcium carbonate No. 15 + 80% calcium carbonate No. 24 + 2.0% calcium carbonate 38 38 45 59 73 50 O / O 2.0 0.73 .0.49 0.81 42 No. 24 + 3.0% calcium carbonate 52 43 No. 24 + 36.5% calcium carbonate 60 44 No. 24 + 70% calcium carbonate 73 45 No. 24 + 80% calcium carbonate 83 460.4% CMC 85/350 + + 1.55% starch MK-1 + 98.05% water 470.5% CMC 85/350 + + 1.55% starch MK-1 + 97.95% water 29 O / O 6.0 0.38 0.24 0.35 35 O / O 4.0 0.63 0.49 0.67 3.25% CMC 85/350% + + 1.55% starch MK-1 + 95.20% water 42 5% CMC 85/350 -F + 1.55% starch MK-1 + 93.45% water48 6% CMC 85/350 + + 1.55% starch MK-G + 92.45% waters55 0.4% CMC 85/600 + + 1.55% collapse. MK-1 + 98.05% water49 0.5% CMC 85/600 4- + 1.55% starch MK-1 + 97.95% starch MK-1 + + 95.20% water 55 O / O 0.5 0.77 0.63 0.99 3/19 a, 5 0,82 0,65 0,98 18/35 0.5 0.85 0.73 0.99 23/52 0.5 0.85 0.75 0.99 O / O 2.5 0.70 0.56 0.76 O / O 2.0 0,69 0,54 0,74 O / O 2.0 0.67 0.53 0.72 O / O 4.0 0.40 0.25 0.38 O / O 2 0.75 0.60 0.79 53 3.25% CMC 85/600 h - + 1.55% starch MK-1 + 95.20% water .60 O / O 0.5 0.80 0.67 54 5% CMC 85/600 + + 1.55% starch MK-1 + 93.45% water 69 0/5 0.5 0.80 0.67 0.93 Editor N. Egorova Compiled by V. Boriskina Tehred A. Kravchuk Order 2722/18 Circulation 633 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 0.93 Proof-reader I.Erdeyi Subscription