Mud circulation system for reducing the swab pressure while tripping out

Patent metadata

Field	Value
Publication number	US-11021919-B2
Application number	US-201916536337-A
Country	US
Kind code	B2
Filing date	Aug 9, 2019
Priority date	Jan 29, 2019
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

The invention provides a mud circulation system for reducing swab pressure while tripping out, including drilling tool components, a normal drilling circulation channel and a tripping circulation channel, the drilling tool components include a drill string, a drill bit, and a top drive, the normal drilling circulation channel includes a first rotary valve, a solid phase control device, a mud tank, a mud pump, and a forth rotary valve connected in sequence, the tripping circulation channel includes a second rotary valve, a tripping mud pump, a tripping mud tank and a third rotary valve connected in sequence; the mud circulation system for reducing the swab pressure is operated to: shut down the mud pump, close the first rotary valve, and open the second rotary valve and the third rotary valve before tripping out; determine the pumping flow rate according to relevant parameters.

First claim

What is claimed is:

1. A mud circulation system for reducing swab pressure while tripping out, including drilling tool components, a normal drilling circulation channel and a tripping circulation channel, wherein:
the drilling tool components include a drill bit, a drill string and a top drive, the drill bit is fixed on a bottom end of the drill string, and the top drive is fixed on a top end of the drill string, the drill bit is used to drill a formation rock, the drill string is used to rotate the drill bit as well as transport the mud from a ground to well bottom, the top drive is used to rotate the drill string;
the normal drilling circulation channel includes a first rotary valve, a solid phase control device, a mud tank, and a mud pump connected in sequence, the first rotary valve is connected with an annulus by a pipe, the solid phase control device is used to eliminate a plurality of solid particles in the mud, an inlet of the mud pump is connected with the mud tank, an outlet of the mud pump is connected with drill string;
the tripping circulation channel includes a second rotary valve, a tripping mud pump, a tripping mud tank and a third rotary valve connected in sequence, the second rotary valve is connected with the drill string, the tripping mud pump is used to drive the mud in the tripping mud tank to flow into the drill string, the third rotary valve is connected with the annulus by the pipe;
the mud circulation system for reducing swab pressure is operated to:
shut down the mud pump, close the first rotary valve, and open the second rotary valve and the third rotary valve before tripping out;
determine a pumping flow rate while tripping out according to relevant parameters, which include a tripping speed, parameters related to the drill string, parameters related to a wellbore and the annulus, and parameters related to the mud;
start the tripping mud pump so that the pumping flow rate gradually reaches and stabilizes the pumping flow rate value;
wherein, the pumping flow rate is determined by
estimating the pumping flow rate for initial guess;
calculating wellbore pressures according to relevant parameters includes the tripping speed, parameters related to the drill string, parameters related to the wellbore and the annulus, and parameters related to the mud, the wellbore pressure is calculated by firstly, determining a flow regime of the mud as laminar or turbulent flow by using a general Reynolds number because most of a plurality of drilling fluids are non-Newtonian, then according to a type of the mud flow regime, calculating the wellbore pressures caused by a frictional effect, frictional term, a gel effect, and an inertial effect, finally, calculating a total wellbore pressure by adding the wellbore pressures caused by the frictional effect, the inertial effect and the gel effect;
comparing the obtained total wellbore pressure with a preset safe wellbore pressure range, if a total wellbore pressure is higher than an upper limit of the safe wellbore pressure range, reducing the estimated pumping flow rate until the total wellbore pressure is within the safe wellbore pressure range, if the total wellbore pressure is lower than a lower limit of the safe wellbore pressure range, increasing the estimated pumping flow rate until the total wellbore pressure is within the safe wellbore pressure range, if the total wellbore pressure is within the safe wellbore pressure range, using the estimated pumping flow rate as the determined value of the pumping flow rate.

2. The mud circulation system according to claim 1 , wherein the drill string includes a drill collar and at least one drill pipe connected in sequence, the drill collar is connected with the drill bit and is used to drive the drill bit to rotate, the drill pipe is connected with the top drive, and is used to drive the drill collar to rotate, the top drive is used to drive the drill pipe to rotate.

3. The mud circulation system according to claim 1 , wherein the normal drilling circulation channel also includes a mud mixing tank, the mud mixing tank, which is connected with the mud tank, is used to add some mixture to the mud tank.

4. The mud circulation system according to claim 1 , wherein the normal drilling circulation channel also includes a waste mud treating tank, the waste mud treating tank, which is connected with the mud tank, is used to collect and treat the waste mud.

Assignees

• Univ Yangtze

Inventors

• Zhang Feifei
• Wang Yidi
• Wang Yuezhi
• Wang Xi
• Li Siyang

Classifications

• E21B21/12

  using drilling pipes with plural fluid passages, e.g. closed circulation systems · CPC title

• E21B44/02 Primary

  Automatic control of the tool feed ({E21B44/005,} E21B44/10 take precedence) · CPC title

• E21B21/00

  Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor (freeing objects stuck in boreholes by flushing E21B31/03) · CPC title

• E21B3/02 Primary

  Surface drives for rotary drilling · CPC title

• E21B19/08

  Apparatus for feeding the rods or cables (E21B19/22 takes precedence; automatic feed E21B44/02); Apparatus for increasing or decreasing the pressure on the drilling tool; Apparatus for counterbalancing the weight of the rods · CPC title