RU2707605C1 - Well cleaning method equipped with plug-in pump - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, in particular, to methods for cleaning of borehole equipped with plug-in pump. Method comprises lowering to the well of a tubing string with a shank and a plug support of a plug-in pump installed above the shank, lowering into the tubing string on pump rods with an anchor mandrel made with possibility of tight interaction with the lock support, lifting of the plug-in pump before opening of the lock support and subsequent flushing of the shank and the well. Bottom of the shank is located in the well at the level providing the most effective cleaning of formation interval during washing. Column of tubing string before lowering above lock support is equipped with expansion with inner diameter, providing sufficient cross-section area with located inside pump for flushing well. Before flushing, plug-in pump is lifted to location in expansion of tubing string.

EFFECT: reduced time expenditures.

1 cl, 3 dwg

Description

The proposal relates to the oil and gas industry, in particular to methods for cleaning a borehole equipped with an in-line pump.

A known method of washing the filter (patent RU No. 2531702, IPC ЕВВ 37/08, published on 10/27/2014 in Bull. No. 30) installed at the well pump intake, including the descent type sucker rod pump equipped with a receiving filter in the sand showing well, stops wells after the filter is clogged and the rod string is lifted; moreover, after the filter is clogged with sand and the well stops, the rod string is partially raised by an amount sufficient to disrupt the pump casing from the castle support and form a concentric flow channel between the pump casing and tubing for the flow of fluid from the pipe string into the well, and hold the rod string in a raised position until the dynamic fluid level in the annulus of the well reaches a static position, after which the rod string is lowered to its initial position and the pump is put into operation .

The disadvantage of this method is the narrow scope due to the possibility of cleaning only filters, while it is impossible to increase the cleaning intensity without a wellhead pump and a small cross section of the passage channel between the pump and tubing.

The closest in technical essence is the method of underground repair of an producing well (patent RU No. 2190756, IPC ЕВВ 37/00, published on 10/10/2002 in Bull. No. 28), containing a casing string, tubing with a liner lowered into the casing string a detachable locking support, which includes an anchor shoe and an anchor mandrel, as well as a plug-in pump mounted on the rods, consisting in the fact that the plug-in pump is lifted from the well, replaced, the tightness of the tubing and split lock support are checked for dirt is flushed with flushing fluid, the plug-in pump is lowered into the tubing with the anchor mandrel in the anchor shoe, the lock support is closed and the produced fluid is pumped, the tubing is left in the well, and the plug-in pump is lowered into the tubing before removing the mud washing liquid, and the detachable lock support is closed after removing the dirt with the washing liquid, the tightness of the tubing and the detachable lock support is checked by pouring flushing fluid into the tubing to the wellhead, and when the level of flushing fluid in the tubing falls excessively, they wipe the detachable locking support, and removing dirt with flushing fluid is done from the shank by opening the detachable locking support and flowing the flushing fluid used to leak testing from tubing to the well, using a volume of flushing fluid greater than the volume of the liner.

The disadvantage of this method is the narrow scope and time-consuming for tripping operations due to the need to completely remove the pump from the well before flushing.

The technical task of the alleged invention is to provide a method for flushing a well equipped with an in-line pump, which saves time and resources due to the lack of the need to completely remove the pump during flushing the well.

The technical problem is solved by a method of cleaning a well equipped with a plug-in pump, including a descent into the well of a tubing string with a liner and a lock support of the plug-in pump installed above the liner, and descent into a tubing string on pump rods with an anchor mandrel, which is capable of tight interaction with a lock support, raising the plug-in pump until the lock support opens and then flushing the liner and well.

What is new is that the bottom of the liner is positioned in the well at a level that ensures the most effective cleaning of the formation interval during flushing, and the tubing string before lowering above the castle support is equipped with an extension with an inner diameter that provides a sufficient cross-sectional area with the flush pump located inside wells, and before flushing raise the plug-in pump to the location in the expansion of the column tubing.

In FIG. 1 shows a diagram of the implementation of the method.

In FIG. 2 shows a section AA of FIG. one.

In FIG. 3 shows the cross-sectional area between the pump and the expansion.

A method of cleaning a well equipped with an insert pump includes descent into a well 1 (Fig. 1) of a tubing string 2 with a liner 3 and a lock support 4 (conventionally shown) of the insert pump 5 installed above the liner 3, and descent into the pump string -compressor pipes on the rods 6 of the pump 5 with an anchor mandrel (not shown), made with the possibility of tight interaction with the castle support 4, raising the plug-in pump 5 to open the castle support 4 and the subsequent washing of the shank 3 and the well 1. The bottom 7 of the shank 3 is located inkvazhine at providing efficient cleaning interval maximum reservoir 8 by washing (determined empirically). The tubing string 2 before descent above the castle support 4 is equipped with an extension 9 with an inner diameter d (Fig. 2), providing a sufficient cross-sectional area S (Fig. 3) with a pump 5 (Fig. 2) located inside to flush the well 1. Moreover, before washing, lift the insert pump 5 to the location in extension 9 (Fig. 1) of the tubing string 2.

Structural elements and technological connections that do not affect the implementation of the method in FIG. 1-3 are not shown or shown conditionally.

The method is implemented in the following sequence.

Based on the operating experience of production wells 1 (Fig. 1) under the same conditions, it is determined at what level from the interval of the formation 1 should the bottom 7 of the liner 3 be located relative to the interval of the formation 8 and which with the productivity it is necessary to pump the flushing liquid into the well 1 for washing the sand plugs 11. Given this performance, empirically determine what cross-sectional area S (Fig. 3) is necessary to ensure the supply of flushing fluid with the least resistance to the flow of flushing fluid with the selected immediately, which implies the inner diameter d (Fig. 2) of the extension 9.

A liner 3 is first lowered into the well 1 (Fig. 1), to which a portion of the tubing string 2 with the locking support 4 is attached from above (the connection point is not shown) 4. An extension 9 is placed above the support (for example, using couplings 10). From above, the whole structure is connected to the second section of the tubing string 2, where it goes down into the well 1 until the bottom 7 of the liner 3 reaches the selected installation level relative to the interval of the reservoir 8. Inside the tubing string 2, the pump 5 on the rods 6 is lowered until the pump anchor 5 with the lock support 4. Rod 6 at the mouth are sealed by wellhead fittings (not shown) and connected to a ground drive (not shown). The ground drive is put into operation and with the help of rods 6, the pump 5 is launched into operation, raising the output of the formation 8 to the surface. With an increase in sand occurrence (determined by laboratory tests of samples - not shown) in the production of formation 8 and / or an increase in the load on the rods 6 (determined by the wellhead weight indicator - not shown), the ground drive is stopped and rods 6 are disconnected from it, which are connected to the lifting mechanism (not shown) and lift until the anchor mandrel of the pump 5 is disconnected from the castle support 4 and the location of the pump 5 in the extension 9. In the well 1 through the annulus of the tubing string 2 flushing fluid is pumped, which erodes the sand plug 11 and the washed sand through the liner 3, the section of the tubing string 2 with the locking support 4, the annular section S (Fig. 2) between the pump 5 and the extension 9 (Fig. 2) carries out the tubing string 2 to the surface. After reducing the sand content in the washing liquid, its injection into the well 1 is stopped. Lower the pump 5 (Fig. 1) on the rods 6 until the anchor mandrel of the pump 5 is tightly connected with the lock support 4. The pump 5 is put into operation by means of a ground drive to select the products of the formation 8 until the next accumulation of sand in the region of the shank 3. The washing cycles start each times, if necessary, clean the well 1 from the sand plug 11.

Compared with the closest analogue, the proposed method allows to reduce the time spent by more than 2 times for flushing a production well, energy - not less than 1.3 times, and time for disassembling and installing wellhead valves - not less than 4 times.

The proposed method of flushing a well equipped with an in-line pump saves time and resources due to the lack of the need to completely remove the pump during flushing the well.

Claims (1)

A method of cleaning a well equipped with an insert pump, including lowering into the well a string of tubing with a liner and a lock support of the plug-in pump installed above the liner, running into the string of tubing on pump rods with an anchor mandrel, which is capable of tight interaction with the lock support raising the plug-in pump to open the lock support and then flushing the liner and well, characterized in that the bottom of the liner is positioned in the well at a level that provides the most effective cleaning of the formation interval during flushing, and the tubing string before lowering above the castle support is equipped with an extension with an inner diameter that provides a sufficient cross-sectional area with the pump inside for flushing the well, and before flushing, the insert pump is raised to the location in the expansion of the pump string -compressor pipes.

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