Emulsion composition for killing gas, gas condensate and oil wells
The invention relates to the oil and gas industry, in particular to the field of operation and maintenance of wells, and can be used as a kill fluid wells. The technical result consists in the development of sustainable heat resistant emulsion composition for plugging gas, gas condensate and oil wells when carrying out repair work, especially in conditions of abnormally low formation pressure, by increasing the viscosity of the composition, its structural and mechanical properties, thixotropic structure and reduction filter to zero under normal conditions, with increasing reservoir temperature up to 80oWith filtering should be no more than 4 cm3/30 min Emulsion composition for killing gas, gas condensate and oil wells contains condensate, emulsifier - amaltal, filler - aluminosilicate microspheres AFM, salt water, and optionally as a thermo stabilizer - gidrofobiziruyuschey silicone fluid NGL-11N when the ratio of components, wt.%: the condensate 25,0 - 30,0; amaltal 4,5 - 5,0; AFM 15,0 - 20,0; NGL-11N 2,5 - 3,0; mineralized water 42,0 - 53,0. table 2. Izopet which can be used as a kill fluid wells.Known liquid plugging of wells containing water filler (lignin), alkali, oil, Ethylenediamine (A. C. the USSR 1175951, 1985).The disadvantage of this fluid are high filtration, insufficient viscosity, low thixotropy, consequently, after killing the well is the deterioration of reservoir properties (FES) of the reservoir, which is unacceptable in the renovations, especially under conditions of abnormally low formation pressure.Known emulsion, including gas condensate, condensed sulfite-alcohol bard (kssb), calcium chloride (l2), sodium carbonate (PA2CO3), urea, chemically precipitated chalk and water (patent RF 2168003, MPK7, E 21 IN 43/12, 2001).One of the main disadvantages of this emulsion composition is that the emulsion is not stable at formation temperatures of 60-80oWith as as emulsifier used condensed sulfite-alcohol bard, do not have good emulsifying properties. In addition, the emulsion comprises chemically precipitated chalk, and after plugging wells it is necessary to conduct the acid treatment wellbore zone (PPP).The closest tehnicheskoy, aluminosilicate microspheres, a surfactant, and water [RF Patent 2176261, MPK7 C 09 K 7/06, 2001] in the following ratio, wt.%: Hydrocarbon liquid - 20,0-52,0 Aluminosilicate microspheres - 2,0-30,0 surfactant - 0,5-0,3 Water Is 77.5-17,7 Disadvantages of this dispersion are low thermostability, high filtering in situ and not use it when jamming wells with reservoir temperature 60,0-80,0oC.The task of the invention is to increase the efficiency of killing the well while maintaining (FES) of the reservoir rocks.The technical result in the claimed invention is to develop a stable heat-resistant emulsion composition for plugging wells when carrying out repair work, especially in conditions of abnormally low, by increasing the viscosity of the composition, its structural and mechanical properties, thixotropic structure and reduction filter to zero under normal conditions; at higher reservoir temperatures up to 80oWith filtering should be no more than 4 cm3/30 minutesThe task and the technical result is achieved by the known emulsion composition for killing gas, gas condensate and oil wells, including the s of the ACM, unlike the prototype contains additionally, as thermo stabilizer, gidrofobiziruyuschey silicone fluid NGL-11N, in the following ratio, wt.%: The condensate - 25,0-30,0 Amaltal - 4,5-5,0 AFM - 15,0-20,0 NGL-11N - 2,5-3,0
Mineralized water - 42,0-53,0
Comparative analysis of the prototype allows us to conclude that the claimed emulsion composition differs from the well-known fact that as a thermo stabilizer it contains gidrofobiziruyuschey silicone fluid on the alcohol-free aqueous-alkaline-based (NGL-11N). In the filter in normal conditions there is no in situ it is not more than 4 cm3/30 min, the emulsion is stable, heat-resistant, and the restitution coefficient of permeability of the reservoir rocks after washing, stimulation and well completion is more than 90%.In the proposed emulsion composition of ingredients in the claimed ratio allows you to get the kill fluid with satisfactory technological parameters.The mutual influence of the components on each other, their Energeticheskie action in this composition allows for minimal filtering, even at high temperatures in reservoir conditions is of habilitator used alcohol-free aqueous-alkaline solution of a water-repelling silicone fluids NGL-11N, produced Novocheboksarsk JSC "Khimprom", on THE other 2229-276-05763441-99.Technical characteristics of the NGL-11N are given in table.1.One of the important factors determining the appropriateness of applying the hydrophobic liquid to improve thermal stability of the proposed emulsion composition is the ability of this reagent to form insoluble in water and oil is finely dispersed precipitates in the reaction with polyvalent salts (in our case - with calcium chloride). The resulting sediment can act as additional "book" element.In the inventive composition of aluminosilicate microspheres act as reducer density, in addition, are builders and participate in the creation of impermeable mud cake, protecting the reservoir from pollution.For experimental verification of the emulsion composition, offer as well killing fluids were prepared emulsion formulations with different amounts of ingredients (table.2).Technology of preparation of the emulsion composition.First, cook salt water, dissolving in water the required amount of calcium chloride. The content of calcium chloride should not be less than 10%, as humanisten by stirring the condensate with an estimated number of amaltal and silicone fluids.After cooking mineral water and hydrocarbon component poured an aqueous solution of salt to the hydrocarbon component and stirred in a mixer for 30 minutes Then in the resulting emulsion is injected required quantity of aluminosilicate microspheres and stirring continued for a further 30 minutesMeasurement of the main parameters of the resulting emulsion is produced on standard devices.The content in the emulsion of the gas in the amount of less than 25% is impractical because of the influence of the electrostatic repulsive forces and a decrease in the rate of adsorption of the emulsifier in the interfacial layer, which makes the emulsion is less stable. The obtained parameters do not satisfy the well conditions.The content in the emulsion gas more than 30% is impractical, as it increases the cost without improving the properties of the emulsion, as well as increased fire risk due to the lower flash point. When a large concentration of gas condensate hindered the adsorption of the emulsifier on the surface and decreases the strength of adsorption.When the concentration of amaltal in the emulsion is less than 4.5% obtained an unstable emulsion, taken as the amount of emulsifier is equl emulsifier. The portion of the surface remains without a protective layer and, over time, molecules coagulate, eventually, the emulsion is destroyed.The content in the emulsion emulsifier in an amount of over 5% is impractical because it will be very stagnant viscous emulsion, the practical application of which is difficult, moreover, increase the energy cost of pumping through the pipes.When the content of aluminosilicate microspheres less than 20% of the density of the emulsion will be close to unity, which is not desirable when the killing of wells in areas of abnormally low.With the increasing content of aluminosilicate microspheres in the emulsion more than 20% of the viscosity of the emulsion increases, which makes it-low-tech, the density of the emulsion is reduced slightly. Therefore, increasing AFM consisting of more than 20% is impractical.In the emulsion composition for killing wells as thermo stabilizer proposed water-repelling silicone fluid NGL-11N. When the concentration of the NGL-11N less than 2.0% decreases thermal stability of the emulsion, fixed on the reduction of the breakdown up to 200-300 C.The optimum content of the NGL-11N to increase thermal stability of the emulsion is about 2.5-3.0%, while the value of the breakdown of Costesti emulsion, associated with increased consumption of reagents. Noticeable improvement of technological parameters not observed.The best parameters of compounds 2 and 3 (table.2).These properties offer emulsion composition (low filter in situ, high-adjustable viscosity, structural, mechanical and thixotropic properties allow you to use it as a kill fluid in the overhaul of wells, especially in conditions of abnormally low formation pressure.Preparation of emulsion composition and technology work on the well are as follows.The chunks of unit CA-320 prepares mineralized water by dissolving the required quantity of calcium chloride (l2).In the second the chunks of unit CA-320 preparing hydrocarbon component of the composition by mixing the condensate with the estimated number of amaltal and silicone fluids.It is mixed hydrocarbon component with mineralized water and stirring for 30 minutes Then in the resulting emulsion is injected required quantity of the microspheres and the stirring is continued for 30 minutesBefore working permit tubing to niranam the volume of the tubing. Then through tubing with an open annular valve emulsion composition is forced up the tubing and in the annulus is calculated overlap a part of the total perforation interval and above. The volume of the emulsion composition for blocking tutu is 5,0-10,0 m3.
Emulsion composition for killing gas, gas condensate and oil wells, including gas condensate, emulsifier - amaltal, salt water and filler - aluminosilicate microspheres AFM, characterized in that it further, as thermo stabilizer, the composition contains gidrofobiziruyuschey silicone fluid NGL-11N in the following ratio, wt.%:
The condensate - 25,0-30,0
Amaltal - 4,5-5,0
AFM - 15,0-20,0
NGL-11N - 2,5 - 3,0
Mineralized water - 42,0-53,0
FIELD: oil and gas production.
SUBSTANCE: composition 61.0-68.9% petroleum or petroleum processing product, 2.0-4.7% natural fatty acid, 2.1-4.0% sodium hydroxide, and natural calcium carbonate with particle size 2 to 50 μm - the rest. Natural fatty acid employs vegetable and animal fat production waste.
EFFECT: enabled killing of well at temperatures up to 80°C with middle and low-permeable reservoirs using inexpensive and accessible domestically available materials allowing oil reservoir properties of producing formations to be preserved.
3 cl, 2 tbl, 2 ex