Device and method for supercritical carbon dioxide high-pressure jet flow plug removal seepage enhancement

Abstract

The invention belongs to the technical field of oil-gas well yield increase equipment and relates to a device and method for supercritical carbon dioxide high-pressure jet flow plug removal seepage enhancement. An oil pipe is sleeved with a casing pipe, a packer is arranged between the casing pipe and the oil pipe, and an exploder is arranged in the oil pipe and connected with the oil pipe; a piston is arranged below the exploder and the portion between the piston and the exploder is filled with propellant; a cylinder sleeve is arranged at the lower end of the piston and the piston moves downwards in the cylinder sleeve; a flow guide connector is arranged on the lower portion of the cylinder sleeve; a nozzle is arranged on the flow guide connector and a rupture disk or an elastic body is arranged on the outlet portion of the nozzle; after the propellant is ignited by the exploder, energy is generated, so that the piston is pushed to compress supercritical carbon dioxide, short-time supercritical carbon dioxide jet flow waves generated through breakage of the rupture disk or popup of the elastic body enable rock to crack initially, and cracks are expanded through the pressure of short-time supercritical carbon dioxide jet flow with the low viscosity of the supercritical carbon dioxide. According to the device and method for supercritical carbon dioxide high-pressure jet flow plug removal seepage enhancement, the structure is simple, operation is convenient, raw materials are easy to obtain, cost is low, the energy use rate is high, and the device and method are environmentally friendly.

Description

Technical field: [0001] The invention belongs to the technical field of production stimulation equipment for oil and gas wells, and relates to a device and process for realizing plugging removal and permeation enhancement in near-well formations of oil and gas wells in one construction, in particular to a supercritical carbon dioxide high-pressure jet flow deblocking and permeation enhancement device and method. Background technique: [0002] In oil and gas production, the formation fluid channel near the wellbore is easily blocked, and the drainage area is small. The permeability of the formation near the wellbore becomes an important factor affecting oil and gas recovery, especially for oil and gas wells polluted by mud after completion. And the old oil and gas wells that have been blocked by various organic and inorganic scales after long-term exploitation have low permeability near the wellbore, resulting in a decline in oil and gas recovery. At present, hydraulic acid fr...

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Problems solved by technology

[0002] In oil and gas production, the formation fluid channel near the wellbore is easily blocked, and the drainage area is small. The permeability of the formation near the wellbore becomes an important factor affecting oil and gas recovery, especially for oil and gas wells polluted by mud after completion. And the old oil and gas wells that have been blocked by various organic and inorganic scales after long-term exploitation have low permeability near the wellbore, resulting in a decline in oil and gas recovery. At present, hydraulic acid fracturing is usually used to create fractures to increase permeability, but The cost of fracturing is high, ranging from a few million to tens of millions, and the effect of increasing permeability is not obvious for tight sandstone gas and shale gas wells in water-sensitive formations. If non-water-based fracturing fluids are used, such as liquid or foam Although the carbon dioxide has a good permeability enhancement effect, the equipment used is complex, the raw materials are expensive, and the cost is high. In addition, the above-mentioned fracturing method has high fracture pressure in hard formations and is easy to damage oil pipes and casings, so it is not suitable for large trucks to enter mountainous, desert and marsh areas

In view of the above shortcomings, relatively low-cost high-energy gas fracturing and synergistic perforation technologies have emerged, but they have not been popularized and applied so far. If the high-energy gas pressure is too high, it will easily damage the casing, and if it is too low, it will not be easy to fracture the formation; the combustion of the propellant is affected by the temperature. , pressure influence, and the pressure is difficult to predict. It is also proposed to bring a strong reducing agent into the formation through a jet to produce acetylene or hydrogen, and then press it into air to generate an explosion to fracture the formation. There are three problems in this method: First, the cost of strong reducing agent Expensive; second, affected by the water content of the formation, the reaction speed of acetylene or hydrogen is difficult to control, and the compressed air is easy to carry the acetylene or hydrogen to the depth of the formation before reaching the explosion limit, which cannot produce explosive cracking effects; For formations with extremely low water content and gas-bearing formations, such as argillaceous shale gas reservoirs, this method is not only difficult to implement, but also the compressed air is easy to react with natural gas, causing well explosion accidents

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