Environmental protection type under-well formation fracturing device

Abstract

The invention relates to an environmental protection type under-well formation fracturing device, belonging to the technical field of permeability improvement fracturing for horizontal wells, inclined shafts and vertical wells. The device comprises a wellhead plugging device, an under-well tugger, in-well packers, a high-pressure hose, an in-well armored cable, a high-strength cable, an operating control mechanism and a sensor assembly. The under-well tugger is operated through the operating control mechanism to drag the two in-well packers to a set position and form a set under-well fracturing formation space, then the high-pressure hose is controlled to respectively pour spacer fluid, a liquid explosive and a primary explosive into an under-well space to be fractured according to the proportion of formula, and the in-well cable is controlled for electronic ignition to carry out the high-energy high-pressure gas fracturing formation operation; through such manipulation, repetitive or non-repetitive formation fracturing operation in different formation spaces and under different formation conditions is realized. The efficient, economic and environmental-protection formation fracturing device is provided for coal bed gas / shale gas mining, the operation fracturing effect is good, fracture extension can form a wide range of fracture system, the permeability and the desorption rate of a reservoir can be increased, and the purpose of increasing production is achieved. The device is worthy of adoption and promotion.

Description

technical field [0001] The environmental-friendly downhole fracturing formation device disclosed by the present invention belongs to the field of anti-permeability fracturing technologies such as horizontal wells, inclined wells, and vertical wells. A new device for downhole composite fracturing formations. Background technique [0002] Coal bed methane and shale gas are all unconventional natural gas. They are clean, high-quality energy and chemical raw materials that have emerged internationally in the past 10 to 20 years. They have great prospects for commercialization. At present, my country's total coalbed methane resources rank third in the world, and shale gas recoverable reserves rank first in the world, both of which are emerging energy industries that my country focuses on. However, affected by tectonic movements, coalbed methane reservoirs in my country usually have the characteristics of low permeability, low pressure, low gas saturation, and strong heterogeneit...

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Problems solved by technology

However, the above methods mostly refer to many theoretical viewpoints in oil and gas exploitation to guide the exploitation of coalbed methane / shale gas. The actual fracturing effect is greatly affected by geological conditions, and the fracturing facilities and construction process are complicated, and the consumption of fracturing materials is large. , high cost, poor controllability, certain potential safety hazards, and more or less irreversible damage and pollution to the formation

Among them, hydraulic fracturing causes water-sensitive pollution to the reservoir, the extension direction of the fracture is controlled by the ground stress, and it is difficult to form a multi-fracture system, which has the characteristics of high cost and damage to the reservoir; Equipment and vehicles, as well as a large construction site and a large number of water sources, and it is easy to form irreversible water locks in some formations

High-energy gas fracturing and multi-stage pulse fracturing technologies have many problems such as small fracturing scale, short fracture length, and inability to add filling sand.

while C0 2 / N 2 Foam fracturing technology often contains thickeners such as guar gum, which will be adsorbed on the surface of the reservoir to block the seepage channel; when fracturing coal reservoirs, due to their relatively shallow burial depth and low reservoir temperature, they often cannot be completely broken in time. The high-viscosity fracturing fluid has great resistance to carry sand forward in the reservoir, and the incomplete gel-breaking fluid or the residue after the gel-breaking has a high solid phase content, which is not suitable for low-permeability fracturing fluids. Deep coal seams do a lot of damage

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