RU1789543C - Method of eliminating paraffin locks in gas condensate wells - Google Patents

Abstract

The invention improves the efficiency of elimination of paraffin plugs by reducing the time and cost of the method in gas condensate wells. For this purpose, the working fluid is taken from the containers using the ADPM-12/150 unit, preheated to 75-80 ° C and fed to one of the inlet pipes of the mixer, and superheated steam brought to 190 ° C in steam-mobile installation (PUF). When leaving the mixer, the working fluid brought to the finest dispersion particles with a temperature of 110-130 ° C is fed into the annulus of the well and pumped until the paraffin plug is completely decomposed. To accelerate the decomposition of the paraffin plug, a working fluid with a temperature of 70-80 ° C is pumped into the borehole space, after which stable condensate is pumped into the borehole space to dissolve the paraffin remaining on the walls of the tubing. Stable condensate is injected in two cycles over a period of 20-30 minutes. The injection volume is determined individually for each well, based on the volume of the tubing. After the last portion of the condensate has been pumped, holding is carried out for 1-2 hours. Then, the development of the well is started. 1 ill. ate with -xj 00 ju SP 4 CJ

Description

The invention relates to the oil and gas industry, in particular, to methods for controlling the deposition of paraffin in elevator pipes during the operation of gas condensate wells under the conditions of oil production.

A known method for dewaxing wells by flushing them with hot oil of various volumes and temperatures 1.

The disadvantage of this method is that it does not allow the removal of resin-paraffin deposits from the inner surface of the tubing, since the paraffin formations are heated through the tubing tubing. Dissolution of resin-paraffin formations WBZ- is only possible at the melting point of paraffin. With a lack of temperature, paraffins melt and slide down the walls of the tubing, creating clogging

traffic jams. In order to create the required temperature throughout the paraffin deposition zone, a significant amount of hot oil must be pumped at a high speed.

The closest way to eliminate paraffin plugs in gas condensate wells. we have taken as type 9,., the method of thermal action by heating the pipes and overhead, as well as washing the pipes and the bottom of the wells with hot liquid, 2.

The disadvantage of this method is its low efficiency, due to the large amount of working fluid and the long processing time of the tubing and bottomhole zone.

The aim of the invention is to improve working conditions and reduce the cost of the method by using heated working fluid and condensate instead of heated oil and injecting high pressure gas to create a gas cushion under the paraffin plug.

This goal is achieved by the fact that in the known method of eliminating paraffin plugs in gas condensate wells, which involves pumping heated working fluid into the annulus and pumping it to complete elimination of the paraffin plug, followed by pumping condensate into the annulus, additionally high pressure gas is injected under the paraffin plug , and as the working fluid use produced water with OP-10, in an amount of 0.2-0.5% per 1 m3. formation water together with superheated steam.

Salient features of the claimed invention in comparison with the prototype are the following:

1. In addition to pumping the working fluid into the annulus, the working fluid is pumped into the pipe space. In the volume of the pump and compressor pipes.

2. As the working fluid, use produced water with an OP-10 blowing agent in an amount of 0.2-0.5% per 1 m3 of working fluid.

3. Before pumping the working fluid into the annulus, high pressure gas is pumped under the paraffin plug.

The drawing shows a diagram of equipment for implementing the method, which depicts containers 1 for storing a working fluid consisting of produced water with a foaming agent. Tanks 1 are connected with a unit 2 for dewaxing wells (ADPM-12 / 150-2), the latter, in turn, is connected with a mixer 3 and through a mixer with a steam-moving unit (PUF) 4.

The mixer 3 is connected at its output end to the annulus of the borehole 5 through the regulator 6. The annular space of the borehole 5 is connected to the tubular space 7.

A method for eliminating paraffin plugs in gas and gas condensate wells. carried out in the following sequence:

Tanks 1 with working fluid were delivered to the well, which were filled and prepared at a special site. Working

the liquid is a mixture of produced water with an OP-10 blowing agent in a ratio of 0.2-0.5% per 1. m3 of produced water.

This ratio is selected empirically.

The number of tanks is determined in each case, based on the volume of the tubing of the well being treated and the annulus

space. It is determined by calculation using known dependencies.

The working fluid using the unit 2 (ADPM-12 / 150-2) is taken from the tanks 1, pre-heated to a temperature of 75-8 0 ° C. Then the working fluid heated to 75-80 ° C is fed to one of the inlet pipes of the mixer 3. At the same time superheated steam, brought to a temperature of 180-200 ° C in a steam-moving

installation (PUF) 4 is fed to another inlet pipe of the mixer 3. When leaving the mixer 3, the working fluid, brought to the smallest dispersion particles with a temperature of 110-130 ° C, is fed into the annulus of the well 5 and pumped until the paraffin plug is completely decomposed. To speed up the decomposition process of the paraffin plug. A working fluid with a temperature of 70-80 ° C is pumped into the pipe space of the well 7, after which stable condensate is pumped into the pipe space of the well to dissolve the paraffin remaining on the walls of the tubing. Stable download

condensate is produced in two cycles for 20-30 minutes. The injection volume is determined individually for each well, based on the volume of tubing

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After the last portion of the condensate has been pumped, an exposure is carried out for 1-2 hours and the development of the well is started.

The invention is illustrated by the following example:

A paraffin plug was discovered in well No. 28 of the Vuktylskoye field at a depth of 679 m from the wellhead. Inner diameter

production casing, Dvn, m 0.168 Diameter HKT.szSHKT, m 0.089 Depth of detection of paraffin plug

from the wellhead, m679 Well depth, m 4215 Formation pressure. MPa 7.86 It is necessary to eliminate the paraffin plug located at a depth of 679 m.

To do this, gas is supplied to the well at a pressure of 5.0 MPa to create a gas cushion under the paraffin plug. 200 thousand m3 of gas was pumped into the annulus of the well.

After that, 100 m3 of working fluid with a temperature of 110 ° C was pumped into the annulus of the well.

Injection of a working fluid comprising a mixture of produced water with an OP-10 foaming agent in a ratio of 0.2% of a foaming agent per 1 m3 of working fluid, which is 2 m3 of an OP-10 foaming agent. was carried out simultaneously with the supply of steam from the PUF 4 with a temperature of 190 ° C through the mixer 3. When leaving the mixer 3, the working fluid brought to the smallest dispersion particles with a temperature of 110 ° C is fed into the annulus of the well 5 and it is pumped until the paraffin plug is completely decomposed . In order to accelerate the decomposition of the paraffin plug, the working fluid at a temperature of 75 ° C is pumped into the pipe space of the well 7, and then stable condensate is pumped into the pipe space of the well to dissolve the paraffin remaining on the walls of the tubing.

Stable condensate is injected in two cycles over a period of 20-30 minutes. The condensate injection volume for this well was 10 m. After the last portion of the condensate was pumped, an exposure was carried out for 2 hours and the well was mastered.

The claimed method in comparison with the prototype has the following advantages:

a) improvement of working conditions;

b) cheaper method.

The method has successfully passed field tests using domestic equipment.

Formula A method for eliminating paraffin plugs in gas condensate wells, including pumping heated working fluid into the annulus and pumping it until the paraffin plug is completely eliminated, followed by pumping condensate into the pipe space, which differs by

that, in order to reduce the cost of the method while improving working conditions, high pressure gas is injected additionally under a paraffin plug, and formation water with OP-10 foaming agent is used in the amount of 0.2-0.5% per 1 m3 of reservoir water together with superheated steam.