Oil-gas well serial double-submersible-electric-pump airtight production pipe column

Abstract

The invention discloses an oil-gas well serial double-submersible-electric-pump airtight production pipe column. The pipe column comprises a casing in an oil production well, an oil pipe in the casing, an underground safety valve which is arranged on the upper portion of the oil pipe and connected with a liquid control pipeline, and a casing packer which is arranged at the bottom of the oil pipe, internally provided with a positioning seal and a guide shoe and provided with a sealing cylinder; a cable production packer, an upper airtight electric submersible pump system, an underground tool direction adjusting device and a lower airtight electric submersible pump system are sequentially connected between the underground safety valve and the positioning seal in series from top to bottom. The upper and lower airtight electric submersible pump systems comprise airtight hangers and airtight system tanks connected with the lower portions of the airtight hangers. The packer is used for isolating stratum liquid from the portion, above the packer, of the casing at a deep position of a shaft, and casing protection liquid can be inserted into an annulus, between the oil pipe and the casing, above the casing packer, so that the production casing is effectively protected and prevented from being eroded by fluids high in sulfur content and high in corrosivity.

Description

technical field [0001] The invention relates to a downhole production pipe string, more specifically, relates to a closed production pipe string of oil and gas wells connected in series with double submersible electric pumps. Background technique [0002] At present, with the development of offshore oil development, the development of high sulfur and high corrosive crude oil fields is on the agenda. In order to prolong the life of such production wells, the anti-corrosion protection of the production casing is particularly important. [0003] Marginal oil fields are usually developed through unmanned platforms or underwater wellheads, relying on the existing central platform pipeline network and processing systems. Because there is no workover rig at the wellhead, special drilling rigs need to be mobilized for pump inspection in such marginal oilfields, which is expensive. Therefore, higher requirements are put forward for the long life of the production string and the red...

AI Technical Summary

Problems solved by technology

[0004] The production casing in offshore oilfields is generally 7", limited by the wellbore space, the conventional "Y" type electric submersible pump production string, the electric submersible pump unit and the bypass pipeline are parallel, and the diameter of the bypass pipe is the same as that of the electric submersible pump unit. The diameter selection needs to be balanced. This structural form of the pipe string limits the selection of large-displacement electric submersible pump units with large diameters, and it is difficult to meet the lifting requirements of large displacement and high power.

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