SU848598A1 - Method of deemulsification of crude oil inside well - Google Patents

Description

The invention relates to a process for the production of hydrocarbon oils, as well as to their treatment in production wells.

In the development of oil fields along with oil from production wells, produced water is extracted, which, mixing with oil, forms high levels of emulsion. The formation of such emulsions occurs in the wells themselves due to the intensive mixing of water-oil mixtures in the underground equipment. The rise of highly viscous emulsions (usually the reverse type) of the day surface, their transportation to the field harvesting system and the subsequent destruction is associated with known difficulties and therefore require significant investment and operating costs in the field farm.

The main way to combat the formation of oil emulsions is

introduction of surface-active substances (surfactants) into the liquid, which contribute to the destruction of the reservation shells on water droplets and the separation of emulsions. The introduction of demulsifier reagents is carried out directly into the production well, in which, due to sufficiently high temperatures, oil is most efficiently demulsified.

ten

The known method of downhole demulsification of oil with various chemical reagents, including the flow of reagent in the production of well fl}.

The disadvantage of the method is

15 in that the delivery of reagents into the well requires the implementation of various design solutions for metering pumps (deep or surface), the installation of which complicates the operation and increases the volume of operational maintenance of the well as a whole. Closest to the proposed. is a method of downhole oil demulsification, including filling the well annulus with reagent, supplying the latter to the oil coming from the reservoir and raising the reagent-treated oil through the pump-compressor pipes 2. The disadvantages of the method are its complexity due to the need to place the reagent tank on the surface It freezes at negative temperatures, which leads to cessation of reagent supply also in reagent overrun, consumption of which is not controlled. The purpose of the invention is ijPo ® ® method and economy of the reagent, when the density of the reagent is higher than the density of oil. This goal is achieved by the fact that a part of the oil pumped by the reagent-treated tubing pipe is fed into the annulus. The drawing shows the implementation of the proposed method. In the flooded wells below the intake of the pump 1 there is always a column of water that accumulates as water flows into the well from the reservoir. Dead oil is located above the pump intake. Through valve 2, a solution of an oil soluble emulsion de-emulsifying agent is poured into the annulus, whose specific gravity does not exceed the proportion of annular oil. The solution is mixed with dead oil due to the presence of diffusion processes in liquids. In addition, some variations in the level of annular oil due to the specific operation of the well and pumping unit contribute to the mixing of oil and reagent. After the supply of the reagent creates a leakage of oil treated with the reagent from the pump pipe 3 into the annulus 4. For example, a leak can be created by partially opening the valve 5, separating the cavity of the pump and casing. Oil treated with reagent. down the stack, additionally with reagent and enters the pump intake, thus delivering the surfactant to the mined product. Taking into account the possibility of filling a large volume of reagent into the annulus and its insignificant amount, carried away by drops of leaks, the period between well treatments can be quite long (for example, 2-3 months). Reagent-processed oil is extracted, on the way to the wellhead, always has a positive temperature, which helps maintain leakage even at low ambient temperatures. The dosage level of the demulsifier to the medium that is reached is monitored by the sedimentation fluid selected at the wellhead. The leakage of the oil treated with the reagent is increased until the complete sediment of the aqueous phase of formation production in the surface conditions occurs. After this valve is reached, the valve element 5 is left in a fixed position. Example. Oil is demulsified in a well equipped with a sucker-rod pump. The flow rate of the well is 38, and the water content is 55%. The well viscous and STOCK 5PO emulsion. The demulsifier R-11 is dissolved in isopropyl alcohol and poured into the well in a volume of 0.67 m. After that, turn off the locking element of the valve 0.5 turns. After 1 day, sludge water is observed in the sampled oil treated with the reagent. Of the total water content in the products, 67% are settled. The rest of the water remains in the oil in the form of fine, fine droplets. Further increase the leakage of the top of the locking element by another 0.25 turn. After 2 days, it starts draining up to 79% of water from its total volume. However, the well production rate drops by more than 20%. Therefore, the valve is returned to the second position, after which the flow rate is restored after 1.5 days. The separation of the phases of water-oil emulsions on the surface of the squadsine is observed for 34 days. In the future, there is a gradual decrease in the effect, right up to the effect of viscous emulsions, indicating depletion of the reagent in the annular fluid. . The application of the proposed method allows reducing reagent consumption and simplifies well servicing.

Claims (2)

1. Patent of the USA 3104716, cl. 166-165,1963. 2. Velikanov A.V. and others. Issues 10 lifting of watering and anhydrous oil by flowing and pumping methods. Kazan, Tatknigoizdat, 1971, with. 134, 135 (prototype). g H-rt / 3S D i tit gtt - (