RU2502776C2 - Reagent for removal of formation fluid containing high-mineralised formation water from gas and gas-condensate wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: use of preparation OC-20 containing mixture of polyoxyethylene glycol esters of synthetic primary higher fatty alcohols with fraction C₁₆-C₁₈; ethoxylated (20 EO) cetyl and stearyl alcohols; oxyethylated (20 EO) hexa (octa) decyl alcohol, non-ionic SAS as solid or liquid reagent for removal of formation fluid with high-mineralised formation water (total mineralisation 100-300 g/l) from gas and gas-condensate wells.

EFFECT: providing effective removal of liquid from gas and gas-condensate wells, in the products of which high-mineralised formation water is contained due to high foam formation degree.

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Description

The present invention relates to the field of gas and gas condensate production, namely, chemical reagents for removing liquid from wells of gas fields (GM), gas condensate fields (HCM), the production of which contains highly mineralized formation water (total mineralization 100-300 g / l) .

Known surfactant (surfactant) "Progress" STO 05807999-007-2006 (1), to remove formation fluid (gas condensate and produced water) from the wells of gas and gas condensate fields.

The disadvantage of this composition is that when the gas condensate in the formation fluid is more than 20% by volume and the presence of formation water with a salinity of more than 30 g / l, the use of surfactants - "Progress" is not effective.

Surfactant - "Progress" is a corrosive reagent, which negatively affects the tubing suspension and downhole equipment.

The closest in technical essence and the achieved result is the reagent Syntanol ALM-10 (TU 2483-003-71150986-2006 (2), Patent RU 2337937, published November 10, 2008 Bull. No. 31 (3)).

However, the scope of Syntanol ALM-10 does not apply to wells in gas and gas condensate fields with highly mineralized formation water in the formation fluid (total mineralization 100-300 g / l).

The aim of the present invention is the provision of effective removal of formation fluid containing highly mineralized formation water (total mineralization of 100-300 g / l) from wells of gas and gas condensate fields using the target surfactant.

This goal is achieved by using liquid or solid (it is a rod with a diameter of 38-40 mm, 40 cm long and weighing 530-550 g) surfactant based on the well-known OS-20 preparation for the first time as a target reagent for removing formation fluid from wells, which meets the criterion "novelty".

The drug OS-20 is a mixture of polyoxyethylene glycol esters of synthetic primary higher fatty alcohols fraction C ₁₆ -C ₁₈ ; ethoxylated (20 EO) cetyl and stearyl alcohols; oxyethylated (20 EO) hexa (octa) decyl alcohol, nonionic surfactant.

The drug OS-20 is certified. It is produced according to GOST-10730-82 (4) and is used as an effective surfactant in the production of synthetic detergents.

The drug OS-20 is a waxy scale from white to yellowish in color with an indicator of the activity of hydrogen ions (pH) in the range of 8.0-10.5. The cloud point of the aqueous solution of the drug with a mass fraction of the main substance of 1% in the range of 90-96 ° C.

The drug OS-20 is a moderately hazardous substance, the 3rd hazard class according to GOST 12.01.007, belongs to the group of biologically soft products.

The use of the well-known OS-20 preparation for removing formation fluid from wells was made possible due to the effect of foaming hydrocarbon-containing fluids containing highly mineralized formation water, established by the authors, using aqueous solutions and solid rods based on the OS-20 preparation.

Studies and analog test tests on the adaptation of the OS-20 preparation to well operating conditions proved:

1. The OS-20 preparation showed stably reproducible results on the effective foaming of highly mineralized formation water (total mineralization from 100 to 300 g / l) of gas and gas condensate wells;

2. Method of application of the OS-20 preparation at the well: working fluid, nonionic liquid surfactant (ZhPAV) in the form of a 10% aqueous solution or solid rods. The concentration of surfactants in the formation fluid is up to 2%, the volume of surfactant working fluid supply into the annulus of the well: from 50 to 100 liters per well operation. Solid surfactants 1-2 units per well operation.

The test results are summarized in table 1.

The data in table 1 indicate the high efficiency of liquid nonionic surfactants based on the drug OS-20. The use of the OS-20 preparation provides the highest degree of pricing of hydrocarbon-containing formation fluids containing highly mineralized formation water.

The use of the well-known OS-20 preparation as a target reagent for removing formation fluid from wells will improve well operating conditions, stabilize and obtain additional gas and condensate production, increase field development efficiency by minimizing the cost of hydrocarbon production, and reducing gas losses.

Table 1 Test results No. p / p Test Surfactant Object of study.
The composition of the reservoir fluid. The concentration of surfactants in the reservoir fluid,% Measurement results Foam ratio
Vania, K The density of the foamed liquid, ρ, g / cm ³ , the nature of the regime of removal one 2 3 four 5 6 ZhPAV-Progress GKM "Shakhpakhty" LLC OK "Zarubezhneftegaz - GPA Central Asia" 0.67 low-efficiency foaming one Produced water with a total salinity of 204 g / l, pH-7.0, density -1.13 g / cm ³ 2.0 1,5 ZhPAV- 0.77 low efficiency 2 Sulfonate Also 2.0 1.3 foaming 3 ZhPAV-Si-ALM-10 -``- 2.0 1,5 0.67 low-efficiency foaming four ZhPAV-OS-20 -``- 2.0 4,5 0.2 effective foaming of formation fluid. Remote mode. 5 ZhPAV-Progress Dubovskoye gas condensate field LLC Gazprom dobycha Krasnodar. Formation water with a total salinity of 100 g / l, pH-6.0, density - 1.065 g / cm ³ 2.0 2.0 0.50 slightly foamed gas-saturated liquid 6 ZhPAV-Sulfonat Also 2.0 1.8 0.55 slightly foamed gas-saturated liquid 7 ZhPAV-Si-ALM-10 -``- 2.0 2,5 0.40 slightly foamed gas-saturated liquid 0.20 effective 8 ZhPAV-OS-20 -``- 2.0 4,5 foaming formation fluid. Remote mode. ZhPAV-Progress LLC Gazpromdobycha Orenburg Orenburg oil and gas condensate field. Formation water 0.77 low-efficiency foaming 9 with total salinity - 250 g / l, pH-5.0, density - 1.168 g / cm ³ 2.0 1.3 10 ZhPAV-Sulfonat Also 2.0 1,2 0.83 low-efficiency foaming eleven ZhPAV-Si-ALM-10 -``- 2.0 2,5 0.40 slightly foamed gas-saturated liquid 12 ZhPAV-OS-20 -``- 2.0 4.0 0.25 effective foaming of formation fluid. Remote mode.

Claims (1)

Reagent (liquid or solid surfactant) for removing formation fluid with highly mineralized formation water (total mineralization 100-300 g / l) from gas and gas condensate wells, based on OS-20 preparation containing a mixture of synthetic primary polyoxyethylene glycol ethers higher fatty alcohols fraction C ₁₆ -C ₁₈ ; ethoxylated (20 EO) cetyl and stearyl alcohols; oxyethylated (20 EO) hexyl (octa) decyl alcohol, a neonogenic surfactant, characterized by the highest degree of foaming (foaming) of hydrocarbon-containing fluids containing highly mineralized formation water of gas and gas condensate wells.