SU956765A1 - Thickened liquid and method of producing the same - Google Patents

Description

The invention relates to the field of oil and gas industry, in particular to thickened compositions and methods for their preparation, and may be; used when conducting hydraulic fracturing.

Known thickened composition containing water and hydrolyzed polyacrylamide 1.

Its disadvantage is low stability in reservoir conditions.

A thickened fluid is known, preferably for fracturing the formation, containing oil, water, and a silicic acid salt additive, obtained by mixing the components 2.

The disadvantage of this fluid is its low stability due to the low gel-structured properties.

The purpose of the invention is to increase the stability of the liquid by improving the gel-structured.

This goal is achieved by the fact that the thickened fluid, mainly for fracturing, containing water, oil and the additive, contains water as an additive.

a solution of sodium carbonate or potassium in the following ratio, wt.%:

Oil 8-20

Aqueous solution of sodium

or potassium 0,001-10

Water The rest, as well as the fact that according to

10 of obtaining a thickened liquid by mixing its components, the oil is mixed with an aqueous solution of 1: 1 carboxy sodium or potassium, and then the rest of the aqueous solution of sodium carbonate (potassium carbonate) is introduced into the resulting mixture, periodically in the amount of 20-30 wt.% by weight

20 originally obtained mixture.

The process of obtaining a thickened liquid is carried out on an installation consisting of a hydraulic cylinder and a propeller mixer.

25

As one of the components, various crude oils are used, in particular, crude oil (Kirmakinskaya; viscosity 158 cP at 20 ° C.

To determine the boundary and

30 average values of the initial substances of the thickened liquid are prepared by 10 samples of the initial formation water with different content of sodium carbonate (Narj, COj). The dissolution of the sodium carbonate and sodium in the formation water is carried out by simple mixing. Each of the ten cooked hphob separately thickened with the above oil. For this purpose, 100 g of sodium carbonate solution are taken from a single prepared sample and placed in a vessel with a stirrer. The crude oil is then added to the solution in the same amount. The liquids are stirred until a viscous hydrophobic mass is obtained, after which the rest of the aqueous solution of sodium carbonate is added to the resulting homogeneous mixture and the mixture is also stirred until a homogeneous hydrophobic gel-structured mass is obtained. In this case, the addition of an aqueous solution of sodium carbonate within the limits mentioned is carried out periodically in an amount of 2030 wt.% Based on the weight of the initially obtained homogeneous hydrophobic mass. The resulting product is a gel-structured mass with a water content of up to 92% by weight. Similarly, gel-structured systems are obtained from the remaining 9 samples of aqueous solutions of sodium carbonate. The thickened product obtained from the first sample (no sodium carbonate in the source water) is also represented by a gel-structured mass, however, its stability is insignificant (about 1-3 hours), and the maximum possible water content in it is 50-70%. If sodium carbonate is present in the source water, the stability of the thickened product increases in direct dependence on the amount of carbonate contained in it (from 2–3 sous to 2–3 months and more). In particular, the thickened product obtained from sample No. 7, lasts for more than 3 months. In the process, the thickening agent is first mixed with a portion of the aqueous carbonate solution, and the amount of the carbonate aqueous solution is taken equal to the amount of the additive. With quantities of an aqueous carbonate solution exceeding a thickening additive, the method is not feasible, in particular, when the ratio of thickening the additive and the aqueous solution of carbonate is 1: 1.5 and higher, respectively. The decrease in the quantitative ratio of the aqueous solution of sodium carbonate is not important, however | time of the process. The need to add an aqueous solution of carbonate in an amount of 20-30 wt.% Of the weight of the initially obtained mixture is due to the fact that in the case of a single addition, the thickening process is not feasible. By adding another portion of the aqueous carbonate solution to more than 30 wt.%, The process of thickening the liquid becomes more complicated and the destruction of the originally prepared mixture is not excluded. A decrease in the amount of added carbonate aqueous solution less than 20 wt.% Does not matter, but it is impractical because of the increase in the time of the thickening process. With a decrease in the amount of carbonate in the source water less than 0.001 wt.%, The stability of the thickened product decreases sharply, an increase in the amount of carbonate in water above 10 wt.% Increases the stability of the thickened product, but it is not expedient from an economic point of view. The proposed method provides for the thickening of various waters with giving them high gel-structured properties of increased stability, the viscosity of which does not depend on the salt composition of water (specific gravity of the thickened product O, 8-1.1 g / cm7) 1. A thickened liquid, mainly dp of hydraulic fracturing, containing water, oil, and an additive, characterized in that, in order to increase its stability by improving its gel-structured properties, as an additive, it contains an aqueous solution of carbonate sodium or potassium in the following ratio, wt.%: Oil8-20 Aqueous solution of sodium carbonate or potassium 0.001-10 Water Remaining 2. A method for producing a thickened liquid by mixing its components, characterized in that the oil is mixed with an aqueous solution of sodium carbonate or potassium in the ratio of 1: 1, then the rest of the aqueous solution of sodium carbonate (potassium) carbonate is introduced into the mixture, the introduction of the latter is carried out periodically in an amount of 20-30 wt.% based on the weight of the initially obtained mixture. Sources of information taken into account in the examination of 9,567 € 5.4 1. Burdin TA and others. Chemistry of oil, gas and formation waters. M., Nedra, 1975, pp.179-181. . 2. USSR author's certificate 687226, cl. E 21 B 43/26, 1977 5 (prototype).

Claims (2)

Claim 1. A thickened fluid, mainly for hydraulic fracturing, containing water, oil and an additive, characterized in that, in order to increase its stability by improving the gel-structured properties, it contains an aqueous solution of sodium or potassium carbonate as an additive in the following ratio of components , weight.%: Oil 8-20 An aqueous solution of sodium carbonate ° or potassium 0,001-10 Water Else 2. A method of obtaining a thickened liquid by mixing its components, characterized in that the oil is mixed with an aqueous solution of sodium or potassium carbonate in a ratio of 1: 1, then the rest of the aqueous solution of sodium carbonate (potassium) is introduced into the mixture within the specified limits, moreover the introduction of the latter is 956765. periodically in the amount of 20-30 wt.% from the weight of the initially obtained mixture.