Temporary plugging agent for staged fracturing of horizontal well and preparation method thereof

Abstract

The invention relates to a temporary plugging agent for the staged fracturing of a horizontal well and a preparation method thereof. The temporary plugging agent consists of the following components of guar gum, aluminum oxide, magnesium oxide, an ammonium persulfate microcapsule gel breaker, sodium polyacrylate spherule and sodium bicarbonate according to a mass ratio of 48:107:193:(11-42):24:1.26. The preparation method comprises the following steps of: mixing the guar gum, the aluminum oxide, the magnesium oxide, the ammonium persulfate microcapsule gel breaker, the sodium polyacrylate spherule and the sodium bicarbonate which serve as raw materials uniformly at room temperature according to the ratio, adding the mixture into water slowly with stirring, and stirring for 5 minutes to obtain the temporary plugging agent for the staged fracturing of the horizontal well. The temporary plugging agent is subjected to a cross-linking reaction at the well temperature of between 60 and 80 DEG C to form a rubber plug with a certain strength, the strength of tolerant differential pressure exceeds 30 MPa, and after fracturing construction is performed, the ammonium persulfate microcapsule gel breaker dissolves out and breaks a cross-linking structure of a guar gum cross-linking system.

Description

technical field [0001] The invention relates to a temporary plugging agent for staged fracturing construction of a horizontal well and a preparation method thereof. Background technique [0002] In the process of oilfield exploitation, the benefits of horizontal wells are far greater than the cost of drilling and completion, and they are more important than vertical wells in the production of heavy oil layers and thick oil layers. The process of horizontal well stimulation involves the use of staged perforation fracturing technology, that is, after the first stage of fracturing is completed, chemical or mechanical methods are used to separate the fractured section from the section to be fractured, so that the target layer be effectively reformed. [0003] Currently used temporary plugging agents mainly include: inert organic resins, solid organic acids (such as benzoic acid used in the United States can slowly dissolve in water and oil), acid-swellable polymers, inert solid...

AI Technical Summary

Problems solved by technology

Among them, polymers and plugging pellets are the most widely used. Among them, the polymer temporary plugging agent has a good plugging effect due to its firm chemical cross-linked network structure, but there is a phenomenon of slow or even difficult gel breaking. If it is not thorough, it will cause a certain degree of damage to the formation; the plugging ball has the characteristics of high plugging strength and small deformation, but the disadvantage is that it is easy to fall off and the plugging effect is poor. Difficult to dissolve