Self-balancing forward and backward continuous cycle operation device

Abstract

The invention discloses a self-balancing forward and backward continuous cycle operation device. The self-balancing forward and backward continuous cycle operation device mainly comprises a direction-changing short joint and a direction-changing well mouth. By designing a center plugging block and a straddle type flow-passing hole structure in the direction-changing short joint, one device can realize forward and backward continuous cycle operation for the first time in China, in this way, on-site adaptability is improved greatly, meanwhile, the area of flow passing is large, too high well mouth back pressure caused by excessive throttling is avoided, and the risk that an operating tool string is blocked and clamped by sand is effectively reduced; by designing a self-balancing motive sealmechanism in the direction-changing well mouth, the two problems are solved that for a long term, a rubber barrel cannot be sealed tightly under acting force, and is prone to being damaged under too large acting force, the construction reliability of oil pipe continuous cycle operation is guaranteed powerfully, and the self-balancing forward and backward continuous cycle operation device can be widely applied to continuous cycle operation of all kinds of oil pipes of oil and gas fields.

Description

Technical field [0001] The invention belongs to the technical field of oilfield workover under casing completion conditions, and specifically relates to a self-balancing positive and negative bidirectional continuous cycle operation device, which is suitable for continuous sand washing or continuous drilling and grinding operations of tubing. Background technique [0002] In the process of oil and gas field development, wellbore sand flushing, well washing, drilling and grinding, etc. are often carried out to achieve the purpose of purifying the wellbore. Under the conditions of tubing construction, in order to reduce the risk of wellhead operations, the "stop pump connection to a single root" method is generally adopted, that is, the pump must be stopped when the faucet is loaded and unloaded, and the single tubing is replaced (see patent 201220176946X for details), causing a brief interruption of the cycle , Resulting in secondary settlement of solid impurities and refilling of...

AI Technical Summary

Problems solved by technology

Under the conditions of tubing construction, in order to reduce the risk of wellhead operations, the method of "stopping the pump and connecting the single tube" is generally adopted, that is, the pump must be stopped when loading and unloading the faucet and replacing the single tube (see patent 201220176946X for details), resulting in short-term interruption of the circulation , leading to the secondary settlement of solid impurities and the formation recharge of the liquid entering the well, which reduces the construction efficiency, increases the risk of pipe sticking, and brings different degrees of pollution to the low-pressure reservoir, especially in the operation of horizontal well measures

[0003] Since the 90s of last century, the pace of research on the continuous circulation operation technology of tubing has not stopped. Patents such as publication number GAI10CN1997E and 2011201512390 have successively given better solutions, but they have not been effectively applied in oil and gas fields. The main problems are as follows: First, the seal of the wellhead device is unreliable, and the wellhead pressure is always in a state of fluctuation. The self-sealing rubber is too tight and is easily scratched by the tubing coupling, which needs to be replaced frequently. 2. The reversing principle of the downhole device is unreasonable. Most of the existing reversing mechanisms are spring check valves. ~100 grades), leading to a significant increase in wellhead back pressure, increasing power loss and well control risks; third, the downhole device flow channel is small (usually no more than 50% of the construction tubing flow area), resulting in throttling While the flow is boosted, it is easy to be blocked by solid impurities in the liquid, resulting in poor circulation channels, and even sand blockage and sand stuck accidents

Fourth, the existing continuous circulation device can only realize single-direction circulation operation. The device described in patent 201220176946X can only realize reverse circulation continuous circulation operation. Time-consuming and labor-intensive, which greatly limits the field applicability of this type of device

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