RU2422623C1 - Procedure for completion of not-cased portion of bore of borehole - Google Patents

Abstract

FIELD: oil and gas production. ^ SUBSTANCE: invention refers to procedure for completion of not-cased portion of bore of borehole in underground formations containing hydrocarbons. The procedure consists in arrangement of a sleeve in a point of the borehole bore, fixed beforehand, in securing the sleeve and in its expansion with a mandrel. Also, the sleeve is made in form of one or several filters with blind notches and corrugated ends. Before expanding the sleeve with the mandrel there is boosted excessive pressure to straighten corrugations on ends of the filters and to fix them relative to walls of the borehole. Local destruction forming slits of the filter occurs in the points of the notches at expansion with the mandrel. Due to absence of holes in the filters rock does not clog inside the filters when assembly is lowered into the borehole. Additionally, slit orifices of the filters formed directly in pay facilitate efficiency of filter operation. ^ EFFECT: favourable conditions at sleeve expansion maintain rigidity of filter shape and facilitate transfer of sleeve along bore of borehole. ^ 9 dwg

Description

The invention relates to the field of well drilling, and in particular to a method for completing the uncased portion of a borehole in underground formations containing hydrocarbons.

To prevent the destruction of the borehole walls, the borehole is fixed by the casing placed in it, which is fastened in the borehole by means of a cement layer between the casing wall and the borehole wall.

To ensure unlimited fluid flow from hydrocarbon-containing formations, the wellbore is not cased in that part that crosses the hydrocarbon-containing formation. If the hydrocarbon containing formation is so weak that it collapses, the uncased part of the wellbore is terminated with a sleeve with slots allowing fluid to flow into the wellbore. Since the inner diameter of the cased part of the bore is smaller than the diameter of the borehole and since the sleeve with slots has to be lowered through the cased part of the borehole, the diameter of the sleeve with slots is smaller than the diameter of the borehole, and as a result, an annular space is formed between the sleeve and the wall of the well. Over time, the formation collapses and falls asleep on the outer wall of the liner, so that the annular space is filled with rock. During hydrocarbon production, the fluid will flow through the formation, through the annular space and through the slots in the liner into the cased wellbore. The circumference through which fluid enters the cased wellbore is thus reduced from the circumference of the wellbore to the circumference of the outer wall of the liner.

The known method of completing the uncased part of the borehole: Device, expandable tubular component and method of their use in the borehole, (patent RU No. 2225497, ЕВВ 29/10, 17 / 08,43 / 08, 43/10, publ. 10.03.04 g ., bull. No. 7). The device has an expandable tubular component that can move into the well in a compressed state and then radially expand to an expanded state. The moving means is capable of moving the expandable tubular component to the desired location in the borehole. The deployment fixture causes the expandable tubular component to expand from its first generally tubular configuration to its second generally tubular configuration.

Its disadvantage is the difficulty in delivering the tubular component to the desired location in the borehole with large curvature and length due to instability of the form at high axial load due to the stuffing of the rock inside the tubular component, since there are cuts in it.

Closest to the proposed one for the majority of coinciding features is a method of completing the uncased part of the wellbore (RF patent No. 2108448, IPC ЕВВ 43/10, publ. 04/10/98, bull. No. 10), which includes placing the sleeve in a predetermined location of the barrel wells, fixing the sleeve and its expansion mandrel.

Its disadvantages are the difficulty in delivering the liner to the desired location in the borehole with large curvature and length due to the instability of the form at high axial load arising due to the stuffing of the rock inside the filter and sludge slots. The rock accumulated in the filter prevents the mandrel from moving when the cartridge expands and can create an emergency situation when the mandrel does not pass. The accumulated rock complicates the development of the well, preventing the flow of fluid through the slots in the filter into the cased wellbore. To eliminate the obstacle to the flow of fluid, it is necessary to study the filter to remove the rock.

The technical problem is the expansion of the application of the method of completing the uncased part of the borehole with large curvature and length; completion of the uncased part of the borehole with increasing filter efficiency; saving time, materials, energy and labor when developing wells.

The technical problem is solved by the method of completing the uncased part of the borehole, including placing the liner in a predetermined location of the wellbore, securing the liner and expanding it with a mandrel.

What is new is that in a cartridge case made in the form of one or several filters with not through notches and corrugated ends, overpressure is created before expansion to expand the corrugations at the ends of the filters with their fixation relative to the well walls, and when the mandrel expands at the notches, local destruction occurs with the formation of filter slots.

Figure 1 shows the sleeve in the transport position with a partial longitudinal section, figure 2 is a section aa of figure 1, figure 3 is a section bB of figure 1, figure 4 shows the fixed sleeve in position c with straightened corrugations with a partial longitudinal section, FIG. 5 is a section BB of FIG. 4, FIG. 6 is a section G-G of FIG. 4, FIG. 7 shows a sleeve in an expanded position with a partial longitudinal section, FIG. 8 is a section DD of FIG. 7, and FIG. 9 is a section EE of FIG. 7.

The arrangement, which implements the method of completing the uncased part of the borehole of the borehole, comprises drill pipes 1 (Fig. 1), to which the upper end 2 of the corrugated pipe 3 is detachably connected. The lower end 4 of the corrugated pipe 3 (Figs. 1 and 2) is rigidly connected with the upper end of the filter 5 (figure 1), equipped with through-cuts 6 (figure 3), and the lower end of the filter 5 (figure 1) is rigidly connected to the next corrugated pipe 7. The number of filters 5 and corrugated pipes 7 is determined by the length of the open part borehole 8. Lower the first end of the lower corrugated pipe 7 is provided with a shoe 9 having a valve through which the cavity 10 of the corrugated pipes 3, 7, filters 5 and drill pipes 1 is filled.

The method of completing the uncased part of the borehole 8 can be divided into three stages. At the first stage, the assembled assembly is lowered to a predetermined location of the wellbore 8. During the descent, the wellbore fluid fills the cavity 10 of the drill pipes 1, corrugated pipes 3, 7, and filters 5 through an existing valve in the shoe 9. Then, under the action of the overpressure created in the drill string pipes 1, corrugated pipes 3, 7 (figure 4) are straightened. In this case, the corrugated pipe 3 (Figs. 4 and 5) is tightly pressed to the inner surface of the casing 11, rigidly fixing the sleeve, and the corrugated pipe 7 (Fig. 4) is pressed tightly to the wall of the borehole 8, centering the filters 5, while there is no local destruction of the filters 5 through non-through notches 6 (Fig.6). Next, creating an axial load, we check the reliability of the fastening of the sleeve to the casing string 10 (figure 4). With reliable fastening of the sleeve to the casing string 11, we unhook the drill pipe string 1 from the upper end 2 of the corrugated pipe 3 and raise the drill pipes 1. The uncased part of the borehole 8 is completed (Fig. 7) by launching an expanding mandrel (not shown) on the drilling pipes 1 (not shown) until the mandrel leaves the lower filter 5. During the movement of the expanding mandrel, the corrugated pipe 3 (Figs. 7 and 8) is tightly pressed against the inner surface of the casing 11, finally firmly fixing the sleeve. Next, the filter 5 is expanded (Fig. 7) with an expanding mandrel, while in the places of the notches 6 (Fig. 6), a local destruction of the filter 5 (Fig. 7) occurs with the formation of slots 12 (Fig. 9). If there are several filters in the layout, then they are expanded from top to bottom.

The extension of the application of the method for completing the uncased part of the borehole with large curvature and length is ensured by the absence of holes in the filters when the assembly is lowered into the well. The absence of holes eliminates the stuffing of the rock inside the filters, which provides favorable conditions for the expansion of the liner, helps to maintain the rigidity of the filter shape and facilitates the movement of the liner along the wellbore. The completion of the uncased part of the borehole with an increase in the efficiency of the filter is ensured by the creation of slot filters directly in the reservoir, which ensures an unhindered flow of fluid from hydrocarbon-containing formations.

By the implementation of the method of completing the uncased part of the borehole, we obtain time, energy and financial costs, materials and labor costs when:

- the manufacture of filters, since their manufacture is carried out only on a lathe;

- reducing the time to run the sleeve except for stuffing the rock inside the filters, which facilitates the movement of the sleeve along the wellbore;

- the exclusion of filter washing operations during well development.

Claims (1)

A method for completing the uncased portion of a borehole, including placing the sleeve in a predetermined location of the wellbore, securing the sleeve and expanding it with a mandrel, characterized in that in the sleeve, made in the form of one or more filters with continuous cuts and corrugated ends, create excess pressure for straightening the corrugations at the ends of the filters with fixing them relative to the walls of the well, and when the mandrel expands in the places of the notches, local destruction occurs with cm filter slits.

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