Constant-flow water injection spray pipe based on mechanical choking principle

Abstract

The invention discloses a constant-flow water injection spray pipe based on a mechanical choking principle. The constant-flow water injection spray pipe comprises a spray pipe shell, wherein a nozzleis arranged on one end of an inner cavity of the spray pipe shell, and is formed by a head contraction section and a throat straight pipe connected sequentially; an upstream installing orifice plate is arranged on one end, located on the head contraction section, of the spray pipe shell; a downstream installing orifice plate is arranged on the other end, located on the head contraction section, ofthe spray pipe shell; a guide rod is arranged in the inner cavity of the spray pipe shell in a penetrating way; a central axis of the guide rod is coincided with a central axis of the spray pipe shell; one end of the guide rod is in threaded connection with a central hole of the upstream installing orifice plate; the other end of the guide rod is in threaded connection with a central hole of thedownstream installing orifice plate; a floater crossing the throat straight pipe so as to control a fluid flow is arranged on the guide rod in a sleeving way. The constant-flow water injection spray pipe based on the mechanical choking principle provided by the invention is simple in structure and convenient to install, the defect of unbalance of water distribution amount caused by different waterabsorbing capacities of various water injection wells or oil layers can be overcome, water is prevented from being injected excessively or insufficiently, fine layered water injection control of an oil field is realized, and the recovery ratio is improved.

Description

technical field [0001] The invention relates to the technical field of fluid flow control, in particular to a constant flow water injection nozzle based on the principle of mechanical choking. Background technique [0002] The main purpose of oil field water injection is to maintain the energy of the oil field, maintain the pressure of the oil layer, improve the liquid supply capacity of the oil field, and achieve the purpose of further oil extraction. It is an important means to achieve high and stable crude oil production. Intensified and effective water injection is the key to improve the oilfield development effect at present. Due to the difference in water absorption capacity and injection requirements among the injection wells, it is necessary to control the flow rate of each injection well. In addition, due to the strong heterogeneity of reservoirs developed by water flooding in my country, layered water injection is an effective method to achieve high and stable pro...

AI Technical Summary

Problems solved by technology

Manually adjusting the valve to control the amount of water injection has two main defects: one is that due to the time lag effect of manual control, the abnormal situation of water injection cannot be dealt with in time, especially at night, due to pressure fluctuations, the operator cannot detect and do it in time. Out of treatment, the water injection volume is out of control or anti-vomiting "backflow", which seriously affects the stable development and safe production of oil fields; on the other hand, most oil fields have water injection pressures between 10 and 40 MPa, which is a high-pressure dangerous environment. Globe valves are vulnerable to damage and leakage, and there are many unsafe factors in practice, and manual adjustment on site is unsafe

The fixed faucet plug has blindness in flow adjustment, and has a low degree of control over the water injection volume, which is likely to cause an imbalance in the water injection volume

However, the existing constant current plugs, such as the structures shown in patents CN200510009708.4, CN95207141.X, CN01237180.7, etc., have problems such as complex structure, difficult processing, large volume and difficult to go into the well, and the spool shape Lines are designed according to experience, without strict mathematical derivation, so there are defects such as low precision of constant current control

[0005] In summary, based on the defects of the existing technology, such as complex structure and low precision of constant flow control, the unbalanced water allocation, over-injection or under-injection of oil layers, the inability to accurately control oilfield water injection, and low water flooding recovery rate have been limited in application. More restrictions

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