SU1388539A1 - Method of drilling wells in hazardous conditions - Google Patents

Abstract

The invention relates to the field of the mining industry and makes it possible to increase the efficiency of the method by eliminating additional sources of pressure and allowing the control of the backpressure in the wellbore. A pumping device (PU) is installed on the drill pipe string W 11 below the static level. In BT 11, the drilling fluid (BR) is injected by the drilling pump, creating a flow of BR in the BT 11 and annulus with PU. Change the movement mode of the BR

Description

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in the open barrel by dividing the flow of it at least two. One of them is directed to the bit through the pipe space and is designed to clean the bottom, and the other into the open borehole through the PU to drive it. The PU is operated as a jet pump, and the flow of BR in the space between the borehole and the PU is created during installation. direction539

The scientific research institute opposite to the flow directed to the open trunk from BT 1I. In this case, the inlet BR is sucked into the lower windows 9 of the lower PU sub, mixes with the flow directed to the PU, and moves along the annulus to the wellhead. The amount of fluid in the flow of BR between the wellbore and PU support for a certain ratio. 3 il.

1 The invention relates to mountainous

production, and more specifically to oil and gas production, and can be used in drilling wells under complicated conditions with pressure regulation of the NIN in the wellbore at the borehole walls.

The purpose of the invention is to increase the efficiency of the method a by eliminating additional pressure sources and ensuring the possibility of controlling the counter-pressure along the wellbore.

Fig. 1 is a schematic diagram explaining a method for drilling wells in the following conditions; Fig. 2 shows a pumping device used in the method of drilling wells under complicated conditions; in FIG. 3 - section A-A in FIG. 2

The essence of the method is that pumping devices are installed on a string of drill pipes, a flow of drilling mud is created in the drill pipes and annulus, and the distance of the movement of mud in the open hole is changed by dividing it into at least two, one of which is directed to bit through the pipe space, and the other into the open borehole through the pumping device to drive it, and the flow of drilling mud in the space between the borehole and the pumping device stvom create the installation site of the latter in the direction opposite to the flow directing emomu in open hole of buoy

pipes, and the amount of fluidity in the flow of drilling fluid in the space between the wellbore and the pumping device is supported by the ratio

Q

Q 1 - Q

g

five

five

five

0

where Q is the amount of fluid in the space between the wellbore and the pumping device, l / s; Q - pumping device delivery, l / s;

Q is the amount of fluid in the flow of drilling fluid in the drill pipe before the separation, l / s.

The pumping device is included in the assembly of drill pipes above the absorption zone, taking into account the penetration of the bit, i.e. so that by the end of the slotting the jet pump does not appear below the absorption zone. ;

The jet pump relieves excess pressure on the absorbing formation and thus prevents absorption. When opening a formation with an abnormally high formation pressure, a jet pump is included in the assembly of the drill string above its roof in the opposite direction, i.e. against the flow of drilling fluid moving from the bottom to the wellhead. In this case, an overpressure is created under the jet pump to prevent the oil and gas supply. The analog is regulated by pressure in zones

borehole prone to collapse.

The pumping device consists of a housing 1, in which a nozzle 2 is installed, three diffusers 3, a distribution chamber 4 with one central 5 and three peripheral nozzles 6 located evenly around the corpus 1 upper 7 and lower 8 with input 9 and output 10 windows. The pumping device is included in the column of pipe 11, having in the lower part of the bit 12.

B drill pipe string pumping mud pump. The drilling fluid moving along the nozzle 2 enters the distribution chamber 4, where it is divided into two streams, one is directed through the central nozzles 5 downwards, the other through nozzles 6, diffusers 3, output openings 10 into the annulus above the pumping device

Due to the release of the drilling fluid at high speed from the nozzles 6 in the space between them and the diffusers 3, a reduced pressure zone is formed into which the drilling fluid from the annulus below the pumping device enters the input holes 9 and is picked up by the flow from The combined stream having the required pressure (pressure energy) through the diffusers 3, the output ports 10 is directed upwards, since the reverse conversion of kinetic energy into pressure energy ends in the diffuser.

The pumping device generates a pressure at the outlet of the diffusers 3, due to which the entire drilling fluid located above the device moves up to the wellhead. The device on the diffuser 3 has a soft characteristic

interconnection of head and performance, with increasing head performance decreases and vice versa. The pressure necessary for raising the drilling fluid to the wellhead and the corresponding performance are provided by the geometrical parameters of the nozzles 6, the diffusers 3 and the amount of drilling fluid supplied to the nozzles 6.

j

0 5

0

0

0

five

The pumping device is inserted into the drill pipe string 11 below the static level Hp-. The solution supplied by the drilling pumps in the pumping device is divided into two streams: one is directed down the tubing to the bit 12 for cleaning the bottom, the other ensures the operation of the pumping device as a jet pump. The drilling fluid rising from the bottom is sucked into the lower windows 9, mixed with the flow; directed to the pumping device, the combined flow with the required flow exits through the windows 10 and moves through the annulus, up to the wellhead, creating a closed loop of circulation of drilling mud. The output of the pumping unit from the pumping device and the flow of drilling fluid moving towards the wellhead form a pillar equal to the distance from the wellhead to the installation depth of this device. Due to the pressure of the forming column, a portion of the drilling fluid from the outlet ports 10 of the device moves back to the inlet ports 9.

A closed cycle of drilling fluid circulation is formed under the condition of equality or excess of the resistance to movement of the drilling fluid from the output windows 10 to the input windows 9 through the annular gap 13 compared to the resistance to movement from the output windows 10 through the annulus to the wellhead.

Claims (1)

Invention Formula A method of drilling wells in complicated conditions, including creating a flow of drilling fluid in the drill pipe and annulus with pumping devices installed along the string of drill pipe and changing the mode of movement of the drilling fluid in the open hole by dividing it at least two, one of which is directed to the bit through the pipe space, and the other into the open well bore through a pumping device for driving it, characterized in that, in order to increase the efficiency of the method and by avoiding additional sources 5138 pressure and allowing adjustment of the back pressure in the wellbore, the flow of drilling fluid in the space between the wellbore and the pumping device is created at the installation site of the latter in the direction opposite to the flow directed to the open hole of the drill pipe, and the amount of fluid in the flow of drilling fluid in the space between the wellbore and the pumping device is supported by the ratio FIG. 2 Compiled by E.Molchanova Editor A.Dolynich Tehred L.Serdyukova Proofreader L.Pilipenko Order 1556/33 Circulation 531Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Q. Qi - Prgde Q - the amount of fluid in the space between the wellbore and the pumping device, l / s; QJ - pumping device delivery, l / s; Q J - the amount of fluid in the flow of drilling fluid in the drill pipe before separation, l / s. fig.Z