GB2176223A - Well fluid expulsion tool - Google Patents

Abstract

A well fluid expulsion tool is used to transport, on wireline/electric line, and then release, at a specified location in a well bore, pressurised gas to affect well fluid expulsion. The cylinder 11 is fitted with a mechanical valve assembly 16 opened by a cog 22 actuated by a ratchet 17 on a sliding sleeve 13. Alternative means of releasing the cylinder contents are provided by substituting the cylinder support coupling and the total mechanical assembly with a modified cylinder support/valve lock-down coupling so that a motorised or clock operated valve can be used. <IMAGE>

Description

SPECIFICATION Well fluid expulsion tool This invention relates to a gas filled, well fluid expulsion tool.

Current techniques used within the oil industry to bring production welis on stream, which are in a 'killed' condition, involve the running of small diameter tubing. Commonly known as coiled tubing, this string is often run to the full working depth of the well. The well is then displaced via this tubing to either a less heavy liquid or an inert gas to create an underbalance of well pressure against reservoir pressure thus initiating well flow.

The use of coiled tubing commonly involves high manpower requirement (3-5 man team), relatively high rig space due to equipment size, and long overall job time due to rigup/rig down, low displacement rates and runin times.

The Well Fluid Expulsion Tool here presented is a wire-line conveyed pressurised gas cylinder with valve configuration and carrier assembly to facilitate gas release at a predetermined location in the well bore. Rapid release of the cylinder contents will result in expulsion of all or part of the fluids above from the well bore. According to prevailing conditions one or more cylinder runs will achieve well underbalance thus bringing the same on stream.

The method of operiing the valve can be varied according to conditions encountered or operator requirements.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows the cylinder with the mechanical valve open assembly attached in the unactivated mode and ready for make-up to wireline prior to running into a well-bore.

Figure 2 shows the cylinder located at a nipple in the wellbore with the mechanical valve opening aasembly in the activated mode.

Figure 3 shows the cylinder configuration when valve actuation by clock mechanism or electric motor is being used.

Referring to drawing 1/2, the expulsion tool comprises a cylinder 11 with latches 19 and a variable diameter landing shoe 15 which is adapted to suit the well 23 configuration.

To open the valve mechanically a sliding sleeve 13, as shown in Figs. 1 and 2 is activated in the following manner. The shear pins 20 which secure the sliding sleeve 13 to the cylinder support coupling 12 while running the tool are broken by jarring action using standard wireline jarring equipment 21 and procedures. The sliding sleeve 13 drops resulting in engagement of the ratchet 17 with the cog 22 on the valve assembly 16. The valve is thereby opened until the sliding sleeve 13 is prevented from further travel by the safety ring 18 as represented in Fig. 2. With the cylinder valve assembly 16 in the open position gas from the cylinder 11 escapes upward via the ported running sub-assembly 14. The sliding sleeve 13 is held in the downward position by the latches 19 to prevent the valve from reclosing.The tool is retrieved from the well in this position thereby ensuring that the expulsion tool is in a safe unpressurised condition for handling.

Referring to drawing 2/2 the expulsion tool as represented by Fig. 3 is shown in the configuration used when actuated by clock mechanism or electric motor. The cylinder 11 is fitted with a variable diameter landing shoe 15 and a cylinder support/valve lock-down coupling 25. The valve lock-down ring 26 secures the ported clock or motor valve assembly 27 to the cylinder 11. To the ported clock or motor valve assembly 27 the clock or motor drive unit 28 is attached. In the case of a motor valve assembly/motor drive unit combination being used the tool will be run into the well fitted to electric line head and cable 29.

1. The Well Fluid Expulsion Tool comprises a pressurised gas cylinder with mechanical, clock or electric motor operated valve assembly(s) which can be actuated after locating the tool at a specified position in a well bore by electric line or wireline.

2. The Well Fluid Expulsion Tool will expel fixed volumes of fluid from the wellbore.

3. The Well Fluid Expulsion Tool can create by means of well fluid expulsion the required drawdown to initiate well flow.

4. The Well Fluid Expulsion Tool requires the presence of only one experienced operator on site for its use.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Well fluid expulsion tool This invention relates to a gas filled, well fluid expulsion tool. Current techniques used within the oil industry to bring production welis on stream, which are in a 'killed' condition, involve the running of small diameter tubing. Commonly known as coiled tubing, this string is often run to the full working depth of the well. The well is then displaced via this tubing to either a less heavy liquid or an inert gas to create an underbalance of well pressure against reservoir pressure thus initiating well flow. The use of coiled tubing commonly involves high manpower requirement (3-5 man team), relatively high rig space due to equipment size, and long overall job time due to rigup/rig down, low displacement rates and runin times. The Well Fluid Expulsion Tool here presented is a wire-line conveyed pressurised gas cylinder with valve configuration and carrier assembly to facilitate gas release at a predetermined location in the well bore. Rapid release of the cylinder contents will result in expulsion of all or part of the fluids above from the well bore. According to prevailing conditions one or more cylinder runs will achieve well underbalance thus bringing the same on stream. The method of operiing the valve can be varied according to conditions encountered or operator requirements. A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows the cylinder with the mechanical valve open assembly attached in the unactivated mode and ready for make-up to wireline prior to running into a well-bore. Figure 2 shows the cylinder located at a nipple in the wellbore with the mechanical valve opening aasembly in the activated mode. Figure 3 shows the cylinder configuration when valve actuation by clock mechanism or electric motor is being used. Referring to drawing 1/2, the expulsion tool comprises a cylinder 11 with latches 19 and a variable diameter landing shoe 15 which is adapted to suit the well 23 configuration. To open the valve mechanically a sliding sleeve 13, as shown in Figs. 1 and 2 is activated in the following manner. The shear pins 20 which secure the sliding sleeve 13 to the cylinder support coupling 12 while running the tool are broken by jarring action using standard wireline jarring equipment 21 and procedures. The sliding sleeve 13 drops resulting in engagement of the ratchet 17 with the cog 22 on the valve assembly 16. The valve is thereby opened until the sliding sleeve 13 is prevented from further travel by the safety ring 18 as represented in Fig. 2. With the cylinder valve assembly 16 in the open position gas from the cylinder 11 escapes upward via the ported running sub-assembly 14. The sliding sleeve 13 is held in the downward position by the latches 19 to prevent the valve from reclosing.The tool is retrieved from the well in this position thereby ensuring that the expulsion tool is in a safe unpressurised condition for handling. Referring to drawing 2/2 the expulsion tool as represented by Fig. 3 is shown in the configuration used when actuated by clock mechanism or electric motor. The cylinder 11 is fitted with a variable diameter landing shoe 15 and a cylinder support/valve lock-down coupling 25. The valve lock-down ring 26 secures the ported clock or motor valve assembly 27 to the cylinder 11. To the ported clock or motor valve assembly 27 the clock or motor drive unit 28 is attached. In the case of a motor valve assembly/motor drive unit combination being used the tool will be run into the well fitted to electric line head and cable 29. CLAIMS

1. The Well Fluid Expulsion Tool comprises a pressurised gas cylinder with mechanical, clock or electric motor operated valve assembly(s) which can be actuated after locating the tool at a specified position in a well bore by electric line or wireline.

2. The Well Fluid Expulsion Tool will expel fixed volumes of fluid from the wellbore.

3. The Well Fluid Expulsion Tool can create by means of well fluid expulsion the required drawdown to initiate well flow.

4. The Well Fluid Expulsion Tool requires the presence of only one experienced operator on site for its use.