SU1432198A1 - Method of preventing salt deposits in lift pipes of gas wells - Google Patents

Abstract

The invention relates to the oil and gas industry and reduces the intensity of salt deposits. Before pumping the surfactant, the water flow rate in the well is measured and acetone in the amount of 0.25–9 ob.ch is pumped into it. on 1 about, h. discharged from the well water. Treatment of formation water with acetone drastically reduces the solubility of sodium chloride in it, which comes out of solution in the well zone and is carried to the surface with a gas stream. 1 dw., 1 tabl e (L

Description

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H oPpeTOiHO relates to the hoftegzovon industrial area. The aim of the invention is to reduce the intensity of salt deposition in elevator tubes,

fla drawing is a diagram of the laboratory setup

The method is implemented as follows.

Before the injection of a surfactant (G1LV), the flow rate of water in the pitcher is measured and acetone in the amount of 0.25–9 v oh per 1 ohm, oh water removed from the well is pumped into it.

The injection of acetone into the wells is carried out continuously using wellhead dispensers of reagents or through inhibitors; then, the wells are treated with solutions of foaming surfactants according to the established technology or continuously by pumping with the help of a mouth of reagent dispensers, pipelines inhibitors, or periodically using mobile units or pipelines of inhibitors.

The proposed method is that when the formation fluid is treated with acetone, the solubility of sodium chloride in it sharply decreases. This leads to the fact that the bulk of the salt is removed from the solution in the well bore zone. A dense sediment on the pipe surface is formed in the case of salt crystallization in the evaporation zone directly on the surface of the riser pipe. If a precipitate forms before the evaporation zone, the previously formed crystalline salt is not included in the SUSPIC salt deposits, but is carried to the surface with a gas stream. When using acetone without surfactant, the crystalline salt is released from the solution in the bottomhole zone. When an acetone solution and water containing salt, in the zone of evaporation first occurs predominant evaporation of acetone. As a result, the concentration of acetone in the solution decreases, which means that the water solubility of the salts is increased. Therefore, salt does not fall on the surface of the pipe until the evaporation of the liquid produces a saturated salt solution. However, there is a crystalline gas stream.

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salt,. As a result of evaporation of the acetone, a salt-unsaturated solution is formed, the crystalline salt dissolves until the solution is not saturated. In the presence of a surfactant, it adsorbs onto the surface of previously formed salt crystals. This leads to a sharp slowdown in the solubility of salt crystals in water. As a result, conditions are created for the formation of incompletely saline solutions in the evaporation zone, which leads to a sharp slowdown in the formation of dense salt deposits in the wells. In the absence of surfactant due to the rapid dissolution of salt crystals during evaporation of acetone, this effect is not observed

Therefore, when surfactants are used together, the rate of formation of dense salt deposits decreases due to the inhibitory effect of surfactants, a decrease in the content of the dissolved salt in the liquid with acetone, and also due to a synergistic effect due to the formation by evaporation of acetone and slowing the solubility of salt crystals in the presence of surfactant

The combined use of scale inhibitors and acetone to prevent the formation of dense salts. sediment unknown

Example 1. The experiment was carried out in a laboratory setup that allows simulating the process of salt formation in the solution evaporation zone. The laboratory setup is a glass container 1 with a capacity of 0.5 liters, equipped with a gas pipe 2 with a metal tip 3 with an internal diameter of 3 mm.

In the container - 300-350 is poured over it with the probe 4. Solution of the gas inlet tube 2 with the metal tip 3 is placed so that it is below the level of solution 4. The tube from the compressor 5 serves air with a flow rate that provides the initial velocity of the gas in tip 3- 10 m / s. Flow is measured by flow meter 6; the solution, getting into the internal cavity of the tip 3, is in contact with the compound according to p.ppgo H (r-ear in rsul1) Tate with (1 zlan) ts ug.popi / i1 utarivaniya G this is Gg coe plgtprl with oG-disagreement (zlt (1 salt of salt. Ja tube formation takes time from the beginning of the process to the gas consumption to the pool.) 150 g of sodium chloride and 30 ml of liquid containing various amounts of water and acetone were taken to prepare the liquid phase. The solution was stirred for 6 h mixer) at the temperature of the bo c in a hermetically sealed vessel. Ali to it, 3 g inhibitor representing the composition ILAB in the following ratio of components, wt%:

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Fatty alcohols of the C, -C, j, jAO fraction Liquid pa11afin15 Water Else. The table presents data on the time of formation of a salt plug in a tube with a different composition of the liquid phase, both in the presence and in the presence of a scale inhibitor. Temperature during the experiments is 60 (

From the results presented in the table, it follows that the greatest technical effect in the joint application of acetone and the inhibitor

deposits are observed in examples 4-10, Toe. when on 1 about, h. water is 0.25 - 9 vol, h. acetone. In this case, the process of scaling compared to using only a scaling inhibitor (a known method) is slowed down by 1.5–3.5 times, and compared to using only acetone, by 4.5–10.5 times.

PRI me R 2c. Implementing a method using a well as an example. The depth of descent of tubing is 1932 m, tubing diameter is 73 mm, and the production string is 146 mm. The inlet pressure in the UKIG is 1.4 MTGa, the reservoir is 4.5 MPa, the gas flow rate is 30 thousand, m7 day water flow rate is 80 l / day, mineralization

water 271 g / l, Intensity) clogging of the tubing with a salt plug - 1 time in 30 - 50 days. After this period, the well stops for preventive maintenance to remove and; salt by pumping a large amount of water and dissolving it. This led to the absorption of well water and the deterioration of collector properties.

The implementation of the proposed method for preventing salt deposition is carried out as follows.

The daily consumption of acetone (at a rate of 0.25 h, acetone per 1 ° C. Water) is determined by the known water flow rate, which will slow the salt deposition rate by 10 times.

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where daily consumption of acetone, l:

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- water flow rate, l / day;

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Sd is the consumption concentration of acetone.

With the help of a mouthpiece of the Tina Lotos reagent dispenser, acetone is continuously pumped into the well of the well, which is working with pipes into the collector, in an amount of 20 l / day,

With the help of a mobile unit, surfactants are pumped into the annulus of the well, for example, 50 liters of a 20% aqueous solution of precella W-OF-100. Z. pumping is carried out periodically 1 time in 15-30 days, according to the technology adopted in the field of fishing.

Claims (1)

Formula of the invention. A method of preventing salt deposits in lift pipes of gas wells, including the injection of a surfactant into the well, characterized in that, in order to reduce the intensity of salt deposition, before the surfactant is injected, the flow rate of the water in the well is pumped and acetone in the amount of 0,25 - At about, h, for 1 ob.h. discharged from the well water. 150 150 150 150 150 150 150 150 150 150 150 150 150 300 300 270 240 210 180 150 120 90 60 JO 150 About 3 3 3 3 3 3 3 3 3 3 about 3 12 14 30 34 40 42 32 28 25 18 4 VNShShI Order 5402/26 Random polygons pr-tie, Uzhgorod, st. Project, 4 / Circulation 531 Subscription