Hole-regulating variable-pressure down-hole choke

Abstract

The invention mainly aims at providing a hole-regulating variable-pressure down-hole choke capable of controlling wellhead pressure through regulating the amount of orifices. The down-hole choke is characterized in that a bayonet, regulating blocks and supporting blocks are sequentially fixed between a central hole and a top cover of a regulating valve; orifices are formed in two sides of the bayonet; a spool is composed of a fixed shaft, a rotating shaft and a moving plug; a support groove group and a plurality of diamond blocks are arranged on the outer wall of the rotating shaft, and the groove group is formed by stepped continuous distribution of a plurality of support grooves of different depths; the spool is limited between the bayonet and the regulating valve, positions of the diamond blocks and the support groove group correspond to positions of the regulating blocks and the supporting blocks respectively, the distance between every two diamond blocks is equal to the width of each regulating block, and the amount of the supporting blocks is identical with the amount of support grooves in the support groove group. The choke can regulate oil pressure through opening and closing wellheads, and setting and releasing construction is not required.

Description

Technical field [0001] The invention relates to a throttling and decompression device for oil and natural gas wells, in particular to a downhole choke that can control wellhead pressure by adjusting the number of throttling holes. Background technique [0002] At present, downhole throttling technology is the main method to prevent hydrate formation during the production of natural gas wells. The main principle of downhole throttling: natural gas passes through the orifice of the throttle to achieve a sudden increase in the volume of natural gas and a decrease in pressure. After the natural gas passes through the orifice, it expands and absorbs formation heat, so that the temperature of the airflow after the throttling can be basically restored to before the throttling The high temperature reduces the probability of natural gas hydrate formation in the wellbore, which guarantees the continuous and stable production of high-pressure natural gas under low-temperature conditions in...

AI Technical Summary

Problems solved by technology

Due to changes in production conditions in the production process, such as formation pressure, surface temperature and the need for production allocation, etc., it is necessary to adjust the throttle parameters downhole. The existing technology is realized by adjusting the diameter of the gas nozzle of the downhole throttle. However, this method has the following defects: the downhole choke needs to be taken out from the well to adjust the diameter of the gas nozzle, and the construction process of setting and unsealing the downhole choke is extremely complicated and prone to failure, so there are problems in field construction. causing greater trouble and affecting the normal production of natural gas wells

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