A new type of oilfield long-term isolation production string

Abstract

The invention belongs to the technical field of oil-field long-acting water exclusion oil exploiting, and particularly relates to a novel oil-field long-acting water-exclusion-oil-exploiting pipe column. The novel oil-field long-acting water-exclusion-oil-exploiting pipe column comprises an oil pipe (1), an oil well pump (2), a tail pipe (5) and a bull plug (6), wherein the oil pipe (1), the oil well pump (2), the tail pipe (5) and the bull plug (6) are sequentially connected from top to bottom, and a specially-made valve (3) and a long-acting water-exclusion-oil-exploiting packer (4) are further sequentially connected between the oil well pump (2) and the tail pipe (5) from top to bottom. According to the pipe column, it is achieved that setting, sub releasing and producing are completed through one pipe column, normal oil exploitation is not influenced in the packing period, and the anti-backflow function is achieved in the pump detecting period; when operation in a well shaft is required, the unblocked performance of the well shaft can be guaranteed only by salvaging the long-acting water-exclusion-oil-exploiting packer through a special tool, the construction procedure is greatly simplified, and construction efficiency is improved.

Description

technical field [0001] The invention relates to the field of long-term production isolation in oilfields, in particular to a novel oilfield long-term production isolation pipe string for backflow prevention, which is suitable for well completion with casing and water discharge from the upper part of the reservoir and water discharge from casing leaks. Background technique [0002] With the continuation of oilfield development time, downhole casings have successively broken due to corrosion and other reasons, resulting in the formation and oil layer connection, affecting the normal development of the oilfield and even polluting the formation water source and damaging the environment. So far, CNPC has accumulated more than 20,000 sets of broken wells . [0003] The commonly used techniques for casing broken wells include casing subsidy, chemical plugging, secondary cementing, and packer isolation. More than 80%. [0004] At present, there are mainly two kinds of production i...

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Problems solved by technology

[0004] At present, there are mainly two types of production isolation technology, one is the conventional production isolation process mainly using conventional production isolation packers such as Y111, Y211, Y341, etc. In this type of process, the packer is mostly directly connected to the The lower end of the pipe string is rigidly connected by thread. During the oil production process, the oil production pipe string bends in the well or the pipe string creeps during the production process, which may easily cause the packer to fail. Once any downhole accessories such as the oil well pump have problems, the packer must be unpacked and started. Out of the pipe string, it is found that this type of packer’s multiple isolation production often leads to extrusion deformation of the set section of the packer, serious corrosion damage, and poor working conditions, which lead to successive shortening or even failure of the isolation production period, so the overall validity period is short , not suitable for oil wells where the distance between the bottom of the artificial well and the liquid surface exceeds 20m and the wells with poor working conditions (the bottom of the well has sedimentary sand or small pieces of falling objects)

The second is the long-life isolation process based on long-life isolation packers such as Y141, Y453, and Y445. In this type of process, the packer needs to be equipped with special setting tools to be lowered first for setting, and then lowered into oil production The pipe string with the intubation tube is normally produced after butt joint, and special tools are used for drilling and grinding when it needs to be pulled out. The construction process is complicated and the cost is high

[0005] The existing patented products of the same kind, such as the water-separated oil production packer ZL200520141928.8, etc., can realize water-separated oil production, but they cannot realize the anti-backflow function after tripping out, resulting in a During the construction of the spacer setting and isolation construction, the water at the casing breakout enters the wellbore and pollutes the formation, which has defects in the process

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