Method for increasing individual-well producing rates of low-permeability wax-bearing oil wells

Abstract

The invention belongs to the technical field of tertiary oil recovery, and particularly relates to a method for increasing individual-well producing rates of low-permeability wax-bearing oil wells.The method particularly includes steps of screening the oil wells; fracturing the oil wells; processing individual-well huff and puff of the oil wells; processing shafts of the oil wells; carrying out field test result evaluation phases.The method has the advantages of simple technologies and high operability, and is favorable for field popularization and application.Besides, the method is high in pertinence, serial technological measures are pertinently selected according to characteristics of the low-permeability wax-bearing oil wells, accordingly, the producing rates of the oil wells can be greatly increased, the valid periods of the oil wells can be greatly prolonged, the individual-well oil increment is higher than 500 t, the valid periods are longer than 3 years, and the input-output ratios are higher than 1:5.In addition, the method can be widely applied to field tests for increasing individual-well producing rates of low-permeability wax-bearing oil wells.

Description

technical field [0001] The invention relates to oil exploitation technology, in particular to a method for increasing single-well production in low-permeability waxy oil wells. Background technique [0002] Low permeability waxy reservoir, the reservoir permeability is lower than 50×10 -3 μm 2 , the wax content of the crude oil in the oil layer is greater than 10%, and the wax precipitation point of the crude oil is higher, which is slightly lower than the temperature of the oil layer; as long as the formation is degassed, the viscosity of the crude oil rises rapidly, and the wax is easy to precipitate in the oil layer. At present, this type of reservoir is generally developed by water injection, but the injection of water is easy to cause cold damage to the oil layer. After the oil layer is waxed, the development effect of water injection will be deteriorated. Therefore, the recovery degree of low permeability waxy oil reservoirs is generally not high at present. , less t...

AI Technical Summary

Problems solved by technology

At present, this type of reservoir is generally developed by water injection, but the injection of water is easy to cause cold damage to the oil layer. After the oil layer is waxed, the development effect of water injection will be deteriorated. Therefore, the recovery degree of low permeability waxy oil reservoirs is generally not high at present. , less than 30%, therefore, there is an urgent need for a method that can significantly increase the recovery of low-permeability waxy reservoirs

[0003] Through literature search, the patent number "ZL03156478.x", titled "The Method of Steam Injection Thermal Recovery for Waxy Low Permeability Reservoirs", introduced a method of producing waxy low permeability reservoirs by combining steam huff and puff and steam flooding. The disadvantages of this invention are: (1) the cost of steam injection thermal recovery is high and the risk is high; (2) the corrosion and maintenance costs of the pipe string are high; (3) due to the low permeability of low permeability reservoirs and the poor fluidity of crude oil, steam injection Thermal recovery has a low rate of enhanced recovery, and the effect is limited; (4) The selection conditions for oil reservoirs are relatively harsh, especially for the thickness and depth of oil reservoirs; (5) High waxy crude oil is lifted in the wellbore During the process, due to the drop in temperature, it is easy to precipitate wax, which will lead to the blockage of the wellbore of the oil well