SU1649212A1 - Method for pumping gas condensate and cocurrent waste water by pipeline - Google Patents

Abstract

The invention relates to the pipeline transport of liquids and can be used in the processes of the disposal of associated field water, transported together with gas condensate in wells. Method for pumping liquid mixtures The invention relates to pipeline transportation of liquids, mainly the gas industry, and can be used to create environmental facilities on the principle of organizing large condensate collection, preparation and disposal of associated field water transported together with gas condensate from a group of gas condensate fields. The aim of the invention is to prevent the formation of hydrate plugs and stable emulsions. the pipeline provides for the transport of the mixture at a consumable volume content of phases in the region of the formation of unstable emulsions. At the same time, a hydration inhibitor is introduced into the feed mixture from the gas treatment plants in the main condensate line at the temperature at which the aqueous phase begins to crystallize in the mixture and in volumes sufficient to prevent it. The mixture is treated with a demulsifier with the flow volume content of phases in the field of formation of resistant emulsions, the value of which is determined by the volume of condensate and water in the gas, measured at the inlet of complex plants and satisfying the expression 0.25 Vr Kf / (Ug Kf + Vr Vf) 0.75, where Vr is the volume of gas that has passed through the metering device when determining condensate and water factors at the inlet of the pipeline to the integrated gas treatment unit, thousand m3 / day; Kf Vf - condensate and water factors in the composition of the test gas, respectively, m3 / m3. 1 il. This goal is achieved in that the hydrate formation inhibitor is introduced into the feed mixture transported in the formation mode of unstable emulsions from complex gas treatment plants into the main condensate conduit at a temperature of the onset of crystallization of the aqueous phase in the mixture in volumes sufficient to prevent it, and the mixture is processed with a demulsifier when the flow volume content of the phases in the field of formation of stable emulsions, the value of which is determined by the value of the volumes

Description

condensate and water in the composition of the gas, measured at the inlet of the complex installations and satisfying the expression UgKf

0.25

0.75,

Vr Cf + Ugvf - J-

where Vr is the volume of gas that has passed through the metering device when determining condensate and water factors at the pipeline entrance to the integrated gas treatment unit, thousand m3 / day;

Kf, Vf - condensate and water factors in the composition of the test gas, respectively, m3 / m3.

The drawing shows the implementation of the proposed method.

The scheme includes the following designations: gas treatment unit 1, which separates the liquid phase from the gaseous gas, plumes of 2 individual pipelines, connecting gas complex treatment plants with the main condensate collection pipeline 3, regional condensate collection point 4 and field production water , pipeline 5 for supplying condensate to a reprocessing station, pipeline 6 for supplying associated production water to regional point 7 for preparation and disposal.

The method is carried out as follows.

The separated liquid mixture of condensate and field water from the gas phase at installations 1 of complex gas preparation is fed through individual trains 2 to the main condensate collection pipeline 3 and then to regional point 4 of condensate collection and field production water. Here, the liquid is stabilized, divided into phases and, after settling, separated streams are sent: condensate for processing through pipeline 5, and production water to the regional preparation and disposal point 7, which should be placed at the same site with point 4, through pipeline 6.

During periods of lowering the ambient temperature to negative values at which the danger of formation of hydrate plugs in pipelines in areas not buried in the ground appears, before the mixture is fed into the main pipeline at each of the complex gas treatment units, the mixture stream is treated with an inhibitor, for example methanol. According to the field practice of gas fields, it was established that the occurrence of hydrate crystals in pipelines not buried in the ground occurs at ambient temperatures of -10 ° C

and below. The consumption of methanol in this case is from 1.5 to 23% of the volume of water in the composition of the mixture, depending on the magnitude of its mineralization. Moreover, the less mineralization, the greater the volume of methanol consumed with equal volumes of water and the mixture. And as practice shows, the consumption of methanol on average up to 20% of the volume of treated water provides for transportation of the mixture without the formation of hydrate plugs. The determination of the amount of methanol used in absolute values is carried out according to the measurement of the water factor in the composition of the gas in a complex installation using the expression VM KVr Bf, where VM is the volume of methanol needed, m3; K is the percentage of methanol in the mixture, fractions of a unit; Vr - the volume of gas passed through the metering device when determining the water factor, thousand m3 / day; Vf - water factor in the composition of the gas, m / m.

The mixture is treated with a demulsifier at a consumable volume content of the phases in the field of formation of stable emulsions, i.e. when the condition

0.25

Ug Kf

-t -, J7-; .. p- 0.75. To this end

V Lt Vr

Periodically, depending on the observed conditions of the behavior of the technological system, the parameters are measured in the given inequality and the following is established.

Example. When measuring, the following parameter values were determined: Vr 5 x x105 m3 day-Kf 2.10 bm3 / m3: HF 2 x x 10 m / m. Substituted data in the specified inequality, we have

5,105 x2

5,105 (2) i. a flowable volume content of the phases was 0.75 and 0.25, which corresponds to the conditions of the development of stable emulsions under which the transportation of the mixture is difficult. In this case, the mixture is treated with a disolvan-type demulsifier at a rate of up to 40-60 g / t.

PRI mme R 2. When measuring, the following parameter values were determined: Vr 5 105 m3 / day; Cf 2 10 6 m3 / m3; HF 0.5x x10 6m3 / m3. Substitute data in the above

inequality,

we have

5 10b X2 10

-6

 0.8, i.e. 5–10 ° X10 (2 + 0.5), the value of the flow volume content of the phases was 0.75, which corresponds to the conditions of the formation of unstable

emulsions in which the treatment of the mixture with a de-emulsifier is not required.

PRI me R 3. When measuring, the following parameter values were determined: Vr 5x x 105 m3 / day: KF + 1.5 m3 / m3, VF 5 10 6 m3 / m3. Substitute data p

 MJ / M. Substitute inequality

we have

5 10s x 1.5 10

-6

-6

 0.23, i.e. by

5 10 X 10 (1.5 + 5), the consumption volume flow rate of the phases was 0.25, which meets the conditions of the region of formation of unstable emulsions, under which the treatment of the mixture with a emulsifier is also not required.

The technical and economic indicators of the method are as follows. Under the conditions of the gas industry, the main waste from the gas field is associated field water extracted together with gas and gas condensate. These waters are classified as harmful to the environment and are subject to isolation from it.

The method is based on the principle of construction of regional collection points and burial of industrial waters. Technologically, this principle is an actual reality and reduces the capital costs of environmental protection measures by 5–10 times, depending on how many individual fields can be connected to one regional location. Moreover, the amount of equipment at the regional collection and disposal site of the commercial waters and capital investments for its construction are practically the same as on the individual. When co-transporting condensate and production water through a pipeline, practically the

0

five

0

5 о 5 0

the same equipment as for the transport of condensate. Therefore, this process will not require any additional costs or technical solutions. The only thing that will be required in this process is the insignificant cost of acquiring the de-emulator and hydrate inhibitor. However, these costs are so small that they cannot be compared with the costs that would be necessary to invest in the construction of individual disposal points.

Claims (1)

Invention Formula The method of pumping gas condensate together with field production water through a pipeline, which involves transporting the mixture in a mode of formation of unstable emulsions characterized in that, in order to prevent the formation of hydrate plugs and stable emulsions, the mixture is processed by a hydration-formation inhibitor at and the demulsification of the mixture is carried out in the field of formation of stable emulsions with a consumable volume content of phases satisfying the expression UgKf 0.25  0.75, Vr Кф + Vr I where Vr is the volume of gas that passed through the metering device when determining condensate and water factors at the inlet of the pipeline to the complex gas treatment unit, thousand m3 / day; Kf, Vf - condensate and water factors, respectively, in the composition of the test gas, m / m. H