Additive for improving wettability of pulverized coal

Abstract

The invention relates to an additive for improving the wettability of pulverized coal, which comprises the following components in percentage by weight: 15 to 40 percent of organic sulfoacid, 10 to 25 percent of fatty alcohol-polyoxyethylene ether, 14 to 35 percent of low-level fatty alcohol, 2 to 15 percent of ethanolamine and 31 to 53 percent of water. The additive is prepared by directly mixing the components at room temperature, can be directly added into liquid for the fracture reformation of coal-bed gas fields, and has mutual solubility with other additives and good compatibility, and is easy to disperse; and the using coal-bed temperature is between 0 and 80 DEG C, the using mass concentration of the additive is between 0.5 to 5 percent, and the additive effectively solves the problem of the effect of the output of the pulverized coal on the energy output of coal-bed gas wells, and promotes the high and stable yield of the coal-bed gas wells.

Description

technical field [0001] The invention relates to a chemical agent for reforming a coal bed gas field, in particular to an additive for improving the wettability of coal powder. technical background [0002] Coal powder is a fine particle falling off the surface of coal rocks. The particle size varies widely, ranging from 1 to 2 mm to about 74 μm, most of which are even finer. The coal powder accumulated in the wellbore is viscous. [0003] The causes of pulverized coal are relatively complicated. Firstly, it is closely related to the properties of coal and rocks. The properties of coal and rocks are very different, especially soft coal, whose structure is more easily broken, and the coal powder formed is far more than that of primary structure coal; secondly, drilling tools grinding and Grinding of fracturing proppant is also an important reason for the generation of coal powder; in addition, the change of stress state may also cause the coal matrix to rupture and produce coa...

AI Technical Summary

Problems solved by technology

The crux of the influence of pulverized coal output on the productivity of CBM wells is mainly reflected in: (1) The migration of pulverized coal directly blocks the natural fracture system of the coal seam or blocks the pores of the proppant filling layer, further reducing the permeability of the coal seam and interfering with the normal production of CBM; , showing the characteristics of significantly reduced water production and almost no desorption or little desorption of coalbed methane; (2) Coal powder clogs the suction port of the pump, causing the valve to be closed tightly and greatly reducing the efficiency of the water pump; (3) Fine coal powder entering the wellbore Gradually accumulate, forming viscous jelly into the pump, which can easily cause the pump to be stuck, and the pump needs to be checked frequently during the production process; (4) Coal powder is easy to accumulate in the shaft of the lower part of the coal seam, and the phenomenon of buried pump is very easy to occur