RU2299981C2 - Method for completion of multi-face branching horizontal wells - Google Patents

Abstract

FIELD: oil extractive industry, namely, technologies for completing construction of multi-face branching horizontal wells with upward direction of horizontal part of shafts (branches) relatively to main shaft and, in particular, completion process when finishing by drilling; may be used also when completing similar multi-face branching horizontal wells after face-adjacent zone processing.

SUBSTANCE: method includes well completion itself with usage of tubing pipes and detection of influx volumes for each shaft. In accordance to invention in horizontal part of well with upwardly oriented shaft branches, completion of each branch is performed without entering the shafts after replacement of drill mud with oil. Tubing pipes are provided with swab limiter and mounted on lower points of each branch. Completion is performed by means of swabbing cycles.

EFFECT: increased productive capabilities of wells by creating system for finishing them by completion of multi-face branching horizontal wells with upward orientation of horizontal part of shafts (branches), with detection of productive capabilities of each branch without entering the shafts.

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Description

The invention relates to the oil industry, and in particular to the field of completion of construction of multi-sided branched-horizontal wells (MRGS) with the direction of the horizontal part of the trunks (branches) upward in relation to the main trunk and, in particular, to the development process when they are finished drilling, and during the development of such MRGS after the work on the treatment of the bottom-hole zone (SCF).

Background to the invention.

An analysis of the current state of the art in this field has shown that currently there are no effective ways to complete the construction of multilateral multilateral horizontal wells (MRGS) with the direction of the horizontal part of the trunks (branches) upward relative to the main trunk. These wells require a special approach to the development process, as traditional methods of developing such branched horizontal wells (RGS) with the descent and entry of equipment into each horizontal well create certain difficulties both in technical terms and in terms of financial costs. The applied methods contribute to the extension of the development time and can lead to the loss of production capabilities of the well.

There is a well completion system for use in separating fluid flows from side wells whose inner ends are in communication with a main well and a method for separating fluid flows from these wells. The system comprises a tubular casing with a plurality of drainage means for receiving fluids coming from side wells. The system is equipped with a flow separator located in the casing, which allows the production of immiscible fluid flows from side wells. (RF patent No. 2136856, IPC class Е21В 43/14, “A well completion system for use in separating fluids from side wells whose inner ends are connected to the main well and a method for separating fluids from these wells” )

The disadvantages of the existing system are:

- the system is applicable in downhole wells and cannot be used in wells with the horizontal part of the trunks pointing upward with respect to the main wellbore;

- sophisticated technology for the performance of work and the use of special equipment;

- the possibility of emergency situations when entering the trunks;

- high economic costs.

A known method of developing "conventional" directional wells, incl. and “ordinary” horizontal wells with one wellbore, involves lowering the tubing with a swab limiter to the lower perforations in “ordinary” wells cased by the production string and to the shoe of the production string in “ordinary” horizontal wells with one horizontal well (RD 39- 0147585-140-96, “Technology for invoking inflow by swabbing during well development”, Bugulma, 1996, p. 29).

The disadvantage of this method is that it is applicable only for single-hole wells, with the direction of the trunks from top to bottom along the section.

Based on the foregoing, the basis of the invention was the task of developing a method for increasing the production capabilities of wells by creating a system for their completion by developing multi-sided branched-horizontal wells with the horizontal direction of the trunks (branches) upward, with the determination of the production capabilities of each branch without entering the trunks.

This task is achieved by the method of developing multilateral multilateral horizontal wells, including the actual development of the well using tubing and determining the volume of inflow of each wellbore, while in the horizontal part of the well with the branches of the trunks pointing up, each branch is developed without entering the trunks after replacement of drilling fluid with oil, tubing is equipped with a swab limiter and installed at the lower points of each branch, at th development courses are conducted swabbing.

The method consists in the fact that after replacing the drilling fluid (in this case, polymer) with oil, tubing pipes are installed with a swab limiter at the bottom bottom point of the last wellbore, one swab cycle is performed with sampling and removal of the level recovery curve (HLC) ) The swab cycle is considered completed upon receipt of oil density corresponding to the saturation of the reservoir according to geological characteristics.

Then, gradually raising the tubing with a swab limiter to the lower points of each branch (trunk), but without entering the branch data, one swab cycle is performed with sampling and removal of the HLW at the lower points of each branch.

The last stage is completed by raising the tubing with a swab limiter to the depths set for swabbing (in accordance with Devonian or sulphurous wells), i.e. above all branches, then produce one cycle (last) of swabbing with sampling and removal of the HLC.

The method of developing multi-hole branched-horizontal wells is illustrated by a scheme that includes a well with branches (trunks), tubing, a shoe of the column, a lubricator, a swab unit, composed of a lift and a swab limiter.

When conducting patent research, no solutions were found that are identical to the claimed one, and therefore, the claimed invention meets the criterion of "novelty."

The essence of the claimed invention does not follow explicitly from the known solutions, thereby the claimed invention meets the criterion of "inventive step".

The proposed method for the development of multi-hole branched-horizontal wells is presented in the drawings, where

- figure 1 is a diagram of the layout of the equipment; stages swabbing MRGS (vertical and horizontal projection);

- figure 2 is a frontal projection MRGS;

- figure 3 is a horizontal projection MRGS.

The method of developing multi-hole branched-horizontal wells is illustrated by the scheme (Fig. 1), which includes a well 1 with trunks I, II, III and IV, with tubing 2, a lubricator device 3, a swab unit arranged from a lift 4 and a swab limiter 5, the shoe of the column 7, “h” is the distance between the lower end 6 of the swab limiter 5 and the shoe of the column 7 and the lower points of the branches 8, 9, 10, 11 of the well 1.

Work on the method of development of multi-hole branched-horizontal wells is as follows.

The wellhead 1 is equipped with a lubricator 3, an oil seal, a spider, shutoff valves, an oil seal control system, a stacker, a check valve (not shown in the figures). At the same time should be provided:

- pressure control in the discharge line and annulus,

- sealing the mouth and extraction of downhole equipment under excess pressure in the well 1,

- preventing air from entering the well 1 during swabbing, well investigation,

- prevention of accidental ejection of downhole equipment during the violent manifestation of well 1 during the inflow call process,

- jamming and well research 1.

At the wellhead 1, a swab unit is installed, consisting of a hoist 4 and a swab limiter 5.

The tubing 2 is lowered into the well 1 with a swab limiter 5 to the lower point of the last branch 11 of the trunk IV. Before the start of swabbing, measure the liquid level in well 1. Then, one swab cycle is performed with the removal of the HLF, while observing the inflow condition

ΔP = P _PL -P _Zab > 0,

where R _pl - reservoir pressure,

- P _zab - bottomhole pressure.

those. create an acceptable depression ΔР per formation, depending on geological conditions.

When the inflow is called during the development of well 1, the level is reduced to a value that creates a possible and acceptable depression for the well in the formation. The recovery of the level in well 1 is monitored to a value calculated by the geological service. Then swabbing again reduce the level and trace the restoration of the level. Swabbing cycles and control of level changes by removing the HIC with sampling are repeated until the flow of products from the formation is stabilized (i.e., until oil is obtained with a density characteristic of the formation).

After mastering the lower point of the last branch 11 of the tubing 2 with the swab limiter 5, raise one lower cycle point of the penultimate branch 10 of the trunk III, without entering this trunk, produce one swab cycle with sampling and removal of HLW.

Then, after swabbing the penultimate branch 10, gradually raising the tubing 2 with a swab limiter 5 to the lower points of each branch 9 and 8 of the trunk II and I, respectively, but without entering these trunks, they make one swab cycle with sampling and removal of the HLF (t. e. at the ninth and eighth lower points of the branches).

The last stage is completed by raising the tubing 2 with a swab limiter 5 to the depths set for swabbing (in accordance with Devonian and sulphurous wells), i.e. above all branches at a distance of "h" from the shoe of column 7, one cycle (the last) is performed with sampling and removal of the HLC.

The obtained HLC data is interpreted for each swab cycle of each lower point of branches 8, 9, 10, and 11, while the production rate of each trunk I, II, III, and IV is determined minus the results of previous cycles. At the last swab stage, the total (total) flow rate of all trunks I, II, III and IV is determined, i.e. flow rate of the well 1.

In all stages of swabbing, it is possible, in the case of gushing, to suppress only a hydrophobic-emulsion solution (GER), or bleed in a line (for this purpose, the construction of the pipeline is completed before the start of swab work, manometers for measuring annular and linear pressure and a lubricator device are installed 3.

The obtained data of each swab cycle for samples and removal of HLF, determination of flow rate [flow rate of each trunk I, II, III, IV (see horizontal projection of figure 1) is determined minus the results of previous cycles], hydraulic conductivity, water permeability, oil permeability, productivity coefficient, reservoir and bottomhole pressure, SKIN-effect, allow to establish the further technological mode of operation and the operability of each barrel, to solve the problems of the need for further SCR and the involvement of any Botha trunk.

With further operation, the repair work of this well and the like is carried out only by hydrophobic-emulsion solutions, or other types of solutions that block the filtration of fluid into the reservoir.

EFFECT: invention provides obtaining parameters of each horizontal part of the trunk for calculating the establishment of a further technological mode of operation, accelerating the input period, preserving the reservoir properties of the production formation, eliminating emergency situations to a minimum.

The technical result is the creation of an easy-to-use, reliable in operation and effective way to develop multi-hole branched-horizontal wells. The advantage of the proposed method over the known is that it provides:

- high-quality work on well development and acceleration of the development process;

- optimal mode of well development and operation;

- increasing well productivity by achieving hydraulic perfection of the productive part of the well;

- reduction of water cut in the period of long-term operation of the wells by ensuring the tightness and reliability of separation and fastening of the reservoirs;

- elimination of the possibility of emergency situations when entering the trunks.

The proposed technical solution allows you to create a flexible and independent system for the development of MGRS, which allows you to set the optimal flow rates for each trunk separately, to conduct independent studies of the state of each trunk.

Another important advantage of the new solution is the elimination of labor-intensive tripping operations accompanying any change in the operating modes of MGRS by traditional methods.

The undoubted advantage of the proposal considered is also the improvement of the environmental situation, since the need for periodic opening of the wellhead and extraction of elements contaminated with oil products is eliminated.

Note that from publicly available information sources (including patent ones), no methods and devices have been identified that are identical to the claimed method for developing multi-sided branched-horizontal wells with a set of essential features, including distinctive, equivalent to the set of essential features of the object of this application.

This allows us to argue that the present technical solution meets the criteria of the invention, and therefore is subject to protection by the title of the invention according to the statement of the authors.

We believe that the information set forth in the application materials is sufficient for the practical implementation of the invention.

Claims (1)

A method for developing multi-hole branched-horizontal wells, including actually developing a well using tubing and determining the inflow volumes of each wellbore, characterized in that in the horizontal part of the well with upright branches, each branch is developed without entering the wells after replacement drilling fluid for oil, tubing is equipped with a swab limiter and installed at the lower points of each branch, while the development of the wire it swab cycles.

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