Urea-assisted SAGD feasibility evaluation experiment device and method

Abstract

The invention provides a urea-assisted SAGD feasibility evaluation experiment device and a urea-assisted SAGD feasibility evaluation experiment method. The urea-assisted SAGD feasibility evaluation experiment device comprises a urea solution injection unit, a pipeline formation simulation unit, a product recovery unit and a temperature and pressure control unit, wherein the urea solution injectionunit comprises a piston container; the pipeline formation simulation unit comprises a heating coil tube and a sand-filled tube; the product recovery unit comprises a dilute sulfuric acid absorption bottle, a gas drying tube and a gas flow meter; and the temperature and pressure control unit comprises a first pressure gauge, a second pressure gauge, a first thermostat, a second thermostat and a counterbalance valve. The urea-assisted SAGD feasibility evaluation experiment device and the urea-assisted SAGD feasibility evaluation experiment method can simulate the temperature and pressure conditions of the SAGD technology, study a pyrolysis conversion rate of a urea solution, determine the influence of temperature and other factors on the pyrolysis conversion rate, and screen suitable operating conditions, thereby fully utilizing the effect of enhancing production of oil by means of urea decomposition products, avoiding damage to the injection pipeline and the reservoir caused by pyrolytic products of the urea solution, and providing a theoretical basis for the application of urea-assisted SAGD development under specific oil reservoir conditions.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploration and development, and relates to a urea-assisted SAGD feasibility evaluation experimental device and method. Background technique [0002] After more than half a century of exploration and development of oil and natural gas resources in my country, the amount of conventional oil resources has become less and less. With the improvement of oil and gas extraction technology and the increase of resource demand, heavy oil resources have been paid more and more attention. Steam-Assisted Gravity Drainage (SAGD), as the main technology of heavy oil recovery, has also achieved commercial application in recent years. However, with the continuous downturn in international oil prices in recent years, the cost of SAGD mining technology remains high, and a large amount of energy and water resources are consumed in the development process, and the economic and environmental benefits need to be furt...

AI Technical Summary

Problems solved by technology

However, urea hydrolyzes at high temperature to generate NH 3 and CO 2 The conversion of is not complete, there will be intermediate reaction, produce a series of by-products such as biuret (C 2 h 5 N 3 o 2 ), melamine (C 3 h 6 N 6 ) and cyanuric acid (C 3 h 3 N 3 o 3 ), etc. These by-products have low solubility under the conditions of SAGD mining temperature (typical temperature: 250°C) and pressure (typical pressure: 4MPa). , the by-products will be precipitated in the form of crystals

The precipitation of by-products may cause blockage of steam equipment pipelines in the process of solvent-assisted SAGD mining, and cause damage to on-site steam units

If the by-products are precipitated in the formation, it will block the pores and seepage channels in the reservoir, reduce the permeability and porosity of the reservoir, and cause certain damage to the reservoir, thus affecting the development effect and recovery factor of SAGD

[0004] At present, there is no relevant research on the law of urea decomposition products in the development process of urea-assisted SAGD at home and abroad. The amount of urea decomposition products under SAGD development conditions is not clear. What kind of temperature, pressure, concentration, flow rate, and catalyst conditions The conversion rate is the highest, and at the same time, it can inhibit the precipitation of by-products, and there is no regular research conclusion

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