Fracturing method for preventing fracturing propping agent of low-permeability horizontal well from reflowing

Abstract

The invention discloses a fracturing method for preventing a fracturing propping agent of a low-permeability horizontal well from reflowing, which is designed for preventing adverse effects caused by the sand production of a horizontal well, that is, the ratio of a tail chase anti-reflowing propping agent, the displacement liquid quantity and the well closing time are optimized according to indoor experiment parameters combined with the stratum closing pressure and temperature of the horizontal well; and consolidation sand is chased in the propping agent by a proportion of 10-20% according to the sand production conditions of blocks of the horizontal well under the conditions of original stratum pressure and temperature on the basis of segmented fracturing of the horizontal well, an anti-reflowing propping agent capable of consolidating without influencing the flow conductivity is pumped into the tail end of a crack, the displacement liquid quantity is 10 m3 more than the conventional replacement quantity, and the well closing time is longer than 60 min. The fracturing method can reduce the stratum sand production rate, is prominent in reflowing effect of the propping agent, can prevent the sand from blocking the pump inspection, and eliminates the adverse effects caused by the sand production of the horizontal well.

Description

technical field [0001] The invention relates to a fracturing method for preventing low-permeability horizontal well fracturing proppant backflow, and belongs to the technical field of oil and gas well fracturing transformation. Background technique [0002] With the rapid development of Changqing Oilfield, the proportion of "Type II and Type III" reservoirs is increasing year by year. Horizontal well development, which is an important means to increase single well production, has become an important way to increase reserves and production in Changqing Oilfield. [0003] For the Changqing low-permeability oilfield, horizontal wells must undergo fracturing in order to gain industrial development value. After the horizontal well is fractured, with the flowback of the fracturing fluid, part of the fracturing proppant is also brought into the wellbore, which will shorten and narrow the propped fractures near the wellbore and reduce the conductivity of the fractures. As a result,...

AI Technical Summary

Problems solved by technology

However, when the closure stress is small, its clamping effect is small, which is not enough to prevent the fracturing sand from returning; and when the closure stress is large, its squeezing effect will intensify the proppant return flow instead.

Changqing Oilfield generally adopts the casing completion method, and the screen sand control technology is not applicable