Fracturing technique for achieving complex crack through multiple particle class differential temporary blocking

Abstract

The invention discloses a fracturing technique for achieving a complex crack through multiple particle class differential temporary blocking, which is fracturing technique that a primary artificial crack is temporarily blocked through rigid temporary plugging agent composition with particle size class differential carried by a fracturing fluid, net pressure in the crack is improved, and a new sidecrack is opened. The fracturing technique comprises the steps that the rigid temporary blocking agent carried by a biodegradable polylactic acid resin-like fiber fracturing fluid with four kinds of particle size class differential combination is fast injected according to the sand mulling concentration of 350-500-650g/cm3, and crack deep part temporary blocking is carried out; the net pressure inthe crack is improved, and the side natural crack is opened, and side remaining oil is effective used; and the oil well single well production and final recovery ratio are improved. The fracturing technique has the advantages that the operability of the construction technique is high, a complex fracture system is fractured to be formed, the using degree of the oil well side remaining oil is improved, the cost is low, and the oilfield development benefit is greatly improved, and solves the difficult problem of the poor repeated fracturing effect of low-permeability reservoirs.

Description

technical field [0001] The invention relates to an oil well repeated fracturing process in the downhole operation technology of oil field exploration and development, in particular to a fracturing process for realizing complex fractures by temporary plugging with multi-grain size differences. Background technique [0002] The Changqing oil and gas field has typical characteristics of low pressure, low permeability, and low production, and most oil fields have been in production for more than 10 years, and some extra-permeable and ultra-low-permeable reservoirs have entered the middle and late stages of development. Due to the development mode of conventional sand fracturing in the initial stage of reservoir exploitation, a single artificial fracture was formed. After a long period of production, the crude oil controlled by early fracturing fractures has been basically exhausted. Crude oil in the lateral (or farther) area of ​​the fracture zone cannot be replenished in time. ...

AI Technical Summary

Problems solved by technology

Because the development mode of conventional sand fracturing was adopted in the initial stage of reservoir exploitation, a single artificial fracture was formed. Crude oil in the lateral (or distant) area of ​​the fracture zone cannot be replenished in time

Due to the development of natural fractures, the direction of water injection is obvious and distributed in strips, the main oil wells are easy to see water, and the long-term effect of lateral oil wells is slow. The technical problem of oil enrichment that is difficult to produce effectively has formed a group of low-yield and low-efficiency wells, presenting the status quo of "low recovery degree, low oil recovery rate, and high decline rate", and the treatment is difficult

In the early stage, conventional old fracture filling was adopted to improve the refracturing technology. Since it is difficult to realize the effective production of lateral remaining oil, the effect of the measures is poor and the decline is large.

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