Screen pipe, string and blockage removing method

Abstract

The invention discloses a screen pipe, a string and a blockage removing method, and relates to the field of oil and gas exploitation. The screen pipe comprises a base pipe, a protecting shell and a pre-filling particle unit; a first opening hole is formed in the side wall of the base pipe; the protecting shell is arranged outside the base tube in a sleeving mode, a second opening hole is formed inthe side wall of the protecting shell, and an annular accommodating cavity is formed between the base pipe and the protecting shell; and the accommodating cavity is filled with the pre-filling particle unit, and the size of the pre-filling particle unit can be changed to be reduced when the preset condition is met. The self-blockage-removing function can be achieved after the screen pipe is blocked, and the oil well productivity is guaranteed.

Description

technical field [0001] The invention relates to the field of oil and gas exploitation, in particular to a screen pipe, a pipe column and a plugging removal method. Background technique [0002] In my country, unconsolidated sandstone reservoirs occupy an important position. For example, there are a large number of such reservoirs in Shengli Oilfield, Liaohe Oilfield, Dagang Oilfield, Bohai Oilfield, and Jidong Oilfield in the Bohai Rim region. This type of reservoir has some common features: shallow burial, relatively weak cementation, and easy sand production during mining. [0003] Mechanical screen sand control is an important sand control method, which mainly includes: slotted screen, high-quality screen, and pre-filled screen. Among them: high-quality screens are suitable for homogeneous reservoirs and reservoirs with low shale content. The disadvantage is that the sand retaining medium is prone to erosion damage, resulting in sand control failure; slotted screens are ...

AI Technical Summary

Problems solved by technology

Among them: high-quality screens are suitable for homogeneous reservoirs and reservoirs with low shale content. The disadvantage is that the sand retaining medium is prone to erosion damage, resulting in sand control failure; slotted screens are simple to process and low in cost, but they are prone to occurrence Due to the restriction of the processing technology, the sand control accuracy is limited, and it is only suitable for reservoirs with relatively coarse sand particle size; the pre-packed screen has the characteristics of partial gravel filling sand control mode, simple processing, convenient installation, suitable for For long horizontal wells, ultra-long horizontal wells and highly deviated wells and other wells that are difficult to carry out gravel packing operations or have high operating costs,

[0004] At present, from the perspective of field use, there are two major problems in the sand control process of mechanical screens: 1. On the one hand, sand control mining in unconsolidated sandstone reservoirs causes screen clogging, which greatly reduces production capacity, and the mechanism of various screen clogging is not clear , have not found a reasonable solution to slow down the screen blockage; 2. On the other hand, the partial blockage of the screen pipe will lead to a decrease in the flow area of ​​the screen pipe, and an increase in the pressure difference and local flow velocity, resulting in erosion damage to the screen pipe , leading to the failure of screen sand control, which is not uncommon in the current offshore oilfield production process

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