Screens, Strings, and Methods for Unplugging

Abstract

The invention discloses a screen pipe, a pipe string and a method for unblocking, and relates to the field of oil and gas exploitation. The screen pipe comprises: a base pipe, a side wall of the base pipe is provided with a first opening; A protective shell outside the tube, the side wall of the protective shell has a second opening, and an annular accommodating cavity is formed between the base pipe and the protective shell; the pre-filled particle unit filled in the accommodating cavity, The volume of the pre-filled particle unit can be changed to shrink when a preset condition is met. The present application can realize the function of self-blocking after the screen pipe is blocked, so as to ensure the productivity of the oil well.

Description

technical field [0001] The invention relates to the field of oil and gas exploitation, in particular to a screen pipe, a pipe string and a method for unblocking. Background technique [0002] In my country, unconsolidated sandstone reservoirs occupy an important position, such as Shengli Oilfield, Liaohe Oilfield, Dagang Oilfield, Bohai Oilfield, Jidong Oilfield, etc. Such reservoirs have some common characteristics: shallow burial, weak cementation, and easy sand production during mining. [0003] As an important sand control method, mechanical screen sand control mainly includes: slotted screen, high-quality screen, and pre-packed 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 simple to process and low in cost, but easy to occur Due to the restriction of processing te...

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 high-inclination 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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