Desanding technology of oilfield flown back fracturing fluid

Abstract

The invention discloses a desanding technology of an oilfield flown back fracturing fluid. The technology is designed to realize the closed continuous desanding, multilevel control and non-grounding desanding of the flown back fracturing fluid. A waste liquid is processed by a cyclone desanding device, the processed waste liquid enters a pressure relief degassing device for gas-liquid separation and filtering sedimentation, the obtained waste liquid is directly pumped into a filter-order filtering device through a first-order water pump, the filtered waste liquid is settled in a sewage pot, the settled filter waste is directly pumped into a second-order filtering device through a second-order water pump and is processed, and the finally obtained product is introduced into a purified water tank. The desanding technology has the advantages of reliable design, simple operation, no need of over-current, and substantial continuous desanding performance, and an apparatus for realizing the technology has the advantages of strong impact resistance, closed processing process, large processing capacity, and high desanding efficiency.

Description

technical field [0001] The invention relates to a sand removal process for oilfield fracturing flowback fluid, and belongs to the technical field of low-permeability oilfield development. Background technique [0002] Since the Changqing Oilfield has always been in a state of low pressure, low abundance and low permeability, it relies on artificial diversion fractures produced by fracturing the formation for production. After the fractured oil well formation is pressure-suppressed, the residual waste liquid in the fracture and oil casing must be flowed back to the ground by the formation pressure. Since the flowback waste fluid is mixed with a large amount of residual fracturing sand and fine gravel after abrasion, sand removal is the primary condition for the repeated reuse of fracturing flowback fluid. [0003] The flowback pressure of on-site fracturing in the oil field can reach 10-20Mpa, and the viscosity of the flowback fluid is all below 10mPa·s. The fracturing grave...

AI Technical Summary

Problems solved by technology

At present, the desanding processes used in oil fields are roughly divided into two categories. One is simple desanding through natural sedimentation and brief filtration. Combined sand removal based on "swirl flow sand removal + inclined plate inclined tube sedimentation + orifice plate seepage + static sedimentation" has complex process, low processing capacity, poor anti-wellhead flowback pressure and impact resistance. During the sand removal process , each component requires a certain flow time, and the equipment cannot be directly connected to the flowback port of the oil well, and the sand removal effect must be achieved by controlling the flow rate at the equipment inlet, which has great limitations in field application

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