RU2278234C1 - Well construction method - Google Patents

Abstract

FIELD: oil industry, particularly for well construction and completion.

SUBSTANCE: method involves drilling well bore up to productive formation roof reaching; arranging bottomhole apparatus in protective case in lower part from outer casing pipe side; communicating bottomhole apparatus with day surface by cable; lowering casing pipe along with cable fastening to outer side of casing pipe; isolating casing pipe interior from protective bottomhole apparatus case interior during casing pipe lowering and cementing; cementing hole annuity; exposing productive formation after casing pipe cementing by drilling-in productive formation with the use of drilling bit having lesser diameter through casing pipe under downbottom parameter control; communicating protective case interior and downhole apparatus with casing pipe interior during drilling-in operation.

EFFECT: increased charge period, possibility to perform measurements with on-line instruments.

1 ex

Description

The invention relates to the oil industry and may find application in the construction and completion of the well.

A known method of well construction, including drilling a wellbore to the top of a producing formation, lowering a casing string, cementing an annulus, drilling an open wellbore into a producing formation from a cased well (RF patent No. 2182651, class E 21 B 43/00, publ. 2002 g.).

The known method allows you to build a well, but does not involve measurements of formation parameters.

Closest to the invention in technical essence is a method of constructing a well, comprising drilling a wellbore, opening a reservoir, lowering and cementing a casing string. The production casing is fastened in the places of the planned studies of the borehole deep parameters and the near-borehole electric logging is carried out by electric dividers of the borehole dipole of the telemetry system with an electromagnetic communication channel installed between the casing pipes of the production casing. During the operation of the well, an autonomous downhole tool is lowered into the production casing with devices for measuring and transmitting depth parameters and fixing in the electric separator, and hydrodynamic and geophysical studies are carried out with the transmission of information to the surface by means of the production casing acting as a borehole dipole, with the upper section of the production casing being electric the separator and the bottom casing section after the electric separator are and measuring electrodes for electric logging of the near-wellbore space (application for invention of the Russian Federation No. 2000123218, class E 21 B 47/00, publ. 08.20.2002 - prototype).

The known method involves measuring the parameters of the reservoir, however, the measurement is carried out by autonomous deep instruments and for a limited time.

The proposed invention solves the problem of increasing the duration of measurements with the transition to measurements with non-autonomous devices.

The problem is solved in that in a method for constructing a well, including drilling a wellbore, opening a producing formation, lowering and cementing a casing string, lowering a downhole tool and measuring the depth parameters, according to the invention, drilling a wellbore is carried out to the top of the productive formation, the downhole device is placed at the bottom on the outside of the casing in a protective casing, the downhole tool is connected by a cable to the surface; when lowering the casing, the cable is fixed to the outside of the casing At the time of descent and cementing, they temporarily disconnect the inner space of the casing string and the inner space of the protective casing with the downhole tool, and the opening of the productive formation is performed after cementing with the drill bit of a smaller diameter by drilling the productive formation with the communication of the inner space of the protective casing and the downhole device with the inner space of the casing .

The features of the invention are

1) drilling a wellbore;

2) drilling a wellbore to the top of the reservoir;

3) placement of the downhole tool in the lower part on the outer side of the casing in a protective casing;

4) connection of the depth device with a cable to the surface;

5) when running the casing, securing the cable to the outside of the casing;

6) for the time of descent and cementing, temporary disconnection of the inner space of the casing and the inner space of the protective casing with the downhole device;

7) casing descent;

8) descent of the downhole tool with the casing and cable on the outside of the casing;

9) cementing;

10) opening the reservoir after cementing by drilling the reservoir with a bit of smaller diameter;

11) the organization of communication of the inner space of the protective casing and the deep device with the inner space of the casing;

12) measurement of downhole parameters during drilling.

Signs 1, 7, 9, 10, are common with the prototype, signs 2-6, 8, 11, 12 are the essential distinguishing features of the invention.

SUMMARY OF THE INVENTION

When conducting measurements of deep parameters, deep devices are placed in the well. At the same time, there is a need to stop the well, raise underground equipment, and when using autonomous devices, there is a delay in the receipt of information, which impedes surgical intervention in the operation of the well or reservoir. The duration of measurements is usually short. The proposed method solves the problem of increasing the duration of measurements with the transition to measurements with non-autonomous devices. The problem is solved as follows.

Drilling a wellbore to the roof of the reservoir. A downhole tool is placed at the bottom on the outside of the casing in a protective casing. Connect the depth device with a cable to the surface. Lower the casing. When lowering the casing string cable on the outside of the casing. For the time of descent and cementing, the inner space of the casing and the inner space of the protective casing are temporarily disconnected with the downhole device.

Cement the annulus. In this case, the protective cover and cable are cemented. The opening of the productive formation is carried out after cementing by drilling the productive formation with a bit of a smaller diameter through the installed casing. When drilling, the inner space of the protective casing and the depth tool is communicated with the inner space of the casing. Thus, at the bottom of the well, a deep stationary device is placed, connected by a cable to the surface. Using this device, measurements of the depth parameters are performed. The device does not interfere with the operation of the well, transmits information to the surface at any time. The duration of measurements is determined by the life of the device.

As a depth device, a depth gauge, a thermometer, a complex device, etc. can be used.

Mechanically destructible hollow plugs, hollow pins, etc., can be used to disconnect and communicate the interior of the protective casing and the downhole tool with the interior of the casing.

Concrete example

Drilling a wellbore to the top of the reservoir at a depth of 1235 m.

Place a PDS depth gauge in the lower part on the outside of the casing with a diameter of 168 mm in a protective casing. The protective casing is made of a steel sheet, which is welded to the bottom pipe of the casing. The cable entry point is sealed with a sealant. Connect the depth device with a cable to the surface. Lower the casing. When lowering the casing string cable on the outside of the casing collars. To preserve the cable, centralizers are installed on the casing. In the casing string at the location of the downhole tool, a technological hole with a diameter of 20 mm is made, which ensures communication between the inner space of the casing and the inner space of the protective casing with the downhole device. For the time of descent and cementing, the inner space of the casing and the inner space of the protective casing are temporarily disconnected with the depth device placing the hollow rivet in the technological hole. Cement the annulus. In this case, the protective cover and cable are cemented. The opening of the productive formation is carried out after cementing by drilling the productive formation with a bit of a smaller diameter equal to 143.9 mm through the installed casing. When drilling, the inner space of the protective casing and the depth tool is communicated with the inner space of the casing by drilling a hollow rivet. Thus, at the bottom of the well place a deep stationary device connected by a cable to the surface. Using this device, measurements of the depth parameters during the drilling and operation of the well, in particular pressure, are performed. The device does not interfere with the operation of the well, transmits information to the surface at any time.

Application of the proposed method will increase the duration of measurements with the transition to measurements with non-autonomous devices.

Claims (1)

A method of constructing a well, including drilling a wellbore, opening a producing formation, lowering and cementing a casing string, lowering a downhole tool and measuring depth parameters, characterized in that the drilling of a wellbore is performed to the roof of the productive formation, the downhole device is placed in the lower part on the outside of the casing the columns in the protective casing, the downhole device is connected by a cable to the surface, when lowering the casing, the cable is fixed on the outside of the casing, for the time of descent and cement Tests temporarily separate the inner space of the casing string and the inner space of the protective casing with the downhole tool, and the opening of the productive formation is performed after cementing with the drill bit of a smaller diameter by drilling the productive formation with the communication of the inner space of the protective casing and the downhole device with the inner space of the casing to control downhole parameters.