Isolation system for equipment maintenance during well treatment opertions

Abstract

Disclosed embodiments include systems and methods for relatively safely providing maintenance for one bank of pumps of a pressurized wellbore services system, even while one or more other bank of pumps continues to operate (e.g. at high pressures). Further, disclosed embodiments may be configured to allow for essentially continuous pumping of fluid downhole in a well, even while maintenance is being performed. Embodiments may also allow relatively safe in situ maintenance operations without the need for separate barrier protection or shielding. For example, banks of pumps may be configured and managed/operated to address red zone concerns, providing relatively safe maintenance opportunities without the need for a barrier therebetween.

1 . A system for pumping fluid downhole into a well, comprises:
 two pump banks fluidly coupled to a wellbore,   wherein each of the pump banks comprises a plurality of pumping units, and   wherein each pump bank has a red zone, and each pump bank is disposed outside the red zone of the other pump bank.   
     
     
         2 . The system of  claim 1 , wherein the two pump banks are disposed with a space therebetween, and the space therebetween is substantially open. 
     
     
         3 . The system of  claim 2 , wherein the two pump banks comprise a first dirty pump bank and a second dirty pump bank. 
     
     
         4 . The system of  claim 3 , wherein each of the first dirty pump bank and the second dirty pump bank comprises the same number of pumping units. 
     
     
         5 . The system of  claim 3 , further comprising a clean pump bank; wherein the clean pump bank comprises a plurality of pumping units; wherein the clean pump bank is fluidly coupled to the first and second dirty pump banks; wherein the first dirty pump bank and the clean pump bank are disposed with a space therebetween, and the space therebetween is substantially open; wherein the second dirty pump bank and the clean pump bank are disposed with a space therebetween, and the space therebetween is substantially open; and wherein at least one of the pump banks is disposed in proximity to the red zone of another of the pump banks. 
     
     
         6 . The system of  claim 5 , wherein the first and second dirty pump banks are each configured to be fluidly isolated from the clean pump bank. 
     
     
         7 . The system of  claim 6 , wherein the clean pump bank is configured to be fluidly isolated from both the first and second dirty pump banks simultaneously. 
     
     
         8 . The system of  claim 3 , wherein each dirty pump bank further comprises one or more high-pressure line; wherein for each dirty pump bank, the one or more high-pressure line comprises a primary high-pressure line, and each of the corresponding plurality of pumping units is fluidly coupled to the corresponding primary high-pressure line for the dirty pump bank; and wherein the primary high-pressure line for the first and second dirty pump banks extend approximately parallel to each other. 
     
     
         9 . The system of  claim 8 , wherein the red zone for the first dirty pump bank does not extend to encompass the primary high-pressure line corresponding to the second dirty pump bank, and the red zone for the second dirty pump bank does not extend to encompass the primary high-pressure line corresponding to the first dirty pump bank. 
     
     
         10 . The system of  claim 7 , further comprising a controller, wherein the controller is configured to control fluid isolation of pump banks in the system. 
     
     
         11 . The system of  claim 3 , wherein the red zone for each pump bank comprises a pressurized equipment red zone and a rotational equipment red zone. 
     
     
         12 . A method for pumping treatment fluid downhole in a well, comprises:
 pumping treatment fluid into the well using a clean pump bank and a first dirty pump bank fluidly coupled in-line, wherein a second dirty pump bank is fluidly isolated from the clean pump bank;   performing maintenance on the isolated second dirty pump bank while both the clean pump bank and the first dirty pump bank are pumping;   wherein a space between the first and second dirty pump banks and between the second dirty pump bank and the clean pump bank is substantially open.   
     
     
         13 . The method of  claim 12 , further comprising, fluidly isolating the second dirty pump bank from the clean pump bank. 
     
     
         14 . The method of  claim 12 , further comprising:
 fluidly isolating the first dirty pump bank;   placing the second dirty pump bank into fluid communication with the clean pump bank;   pumping treatment fluid into the well using the clean pump bank and the second dirty pump bank, while the first dirty pump bank is fluidly isolated; and   performing maintenance on the isolated first dirty pump bank while pumping with both the clean pump bank and the second dirty pump bank.   
     
     
         15 . The method of  claim 12 , further comprising:
 fluidly isolating the clean pump bank from both the first and second dirty pump banks and placing the second dirty pump bank into fluid communication with the well;   pumping treatment fluid into the well using the first and second dirty pump banks, while the clean pump bank is fluidly isolated;   performing maintenance on the clean pump bank while pumping with both the first dirty pump bank and the second dirty pump bank.   
     
     
         16 . The method of  claim 15 , further comprising, after maintenance is performed on the clean pump bank, fluidly isolating one of the dirty pump banks while placing the clean pump bank into fluid communication with the other dirty pump bank and the well. 
     
     
         17 . The method of  claim 15 , wherein maintenance is performed on the first and second dirty pump banks based on a dirty pump bank maintenance schedule, and maintenance is performed on the clean pump bank based on a clean pump bank maintenance schedule, wherein the clean pump bank maintenance schedule has less frequent maintenance than the dirty pump bank maintenance schedule. 
     
     
         18 . The method of  claim 15 , wherein responsive to the clean pump bank being isolated for maintenance and both dirty pump banks pumping fluid to the well, altering the composition of the dirty fluid supplied to the dirty pump banks to maintain approximately the same composition of treatment fluid flowing to the well. 
     
     
         19 . The method of  claim 16 , wherein responsive to the clean pump bank being placed into fluid communication with one of the dirty pump banks and one of the dirty pump banks being fluidly isolated for maintenance, altering the composition of the dirty fluid supplied to the dirty pump bank in fluid communication with the clean pump bank and the well, to maintain approximately the same composition of treatment fluid flowing to the well. 
     
     
         20 . A method of setting up a well site, comprising:
 transporting a first plurality of pumping units to the well site;   transporting a second plurality of pumping units to the well site;   transporting a third plurality of pumping units to the well site;   positioning the first plurality of pumping units as a first dirty pump bank at a first location at the well site, wherein the first dirty pump bank comprises a first red zone;   positioning the second plurality of pumping units as a second dirty pump bank at a second location at the well site, wherein the second dirty pump bank comprises a second red zone, and wherein the second dirty pump bank is disposed outside of the first red zone;   positioning the third plurality of pumping units as a clean pump bank at a third location at the well site, wherein the clean pump bank comprises a third red zone, and wherein the clean pump bank is disposed outside of both the first red zone and the second red zone;   fluidly coupling the clean pump bank to both the first dirty pump bank and the second dirty pump bank;   fluidly coupling the clean pump bank and both the first and second dirty pump banks to the well;   wherein the fluid coupling is configured to allow fluid isolation of the clean pump bank from the first and second dirty pump banks for maintenance, the fluid coupling is configured to allow fluid isolation of the first dirty pump bank from the clean pump bank and the well for maintenance, and the fluid coupling is configured to allow fluid isolation of the second dirty pump bank from the clean pump bank and the well for maintenance; and   wherein a substantially open space is disposed between the second dirty pump bank and the first dirty pump bank; and a substantially open space is disposed between the clean pump bank and at least one of the first and second dirty pump banks.   
     
     
         21 . The method of  claim 20 , wherein positioning the pump banks comprises disposing the pump banks so that at least one of the pump banks is disposed in proximity to the red zone of another of the pump banks. 
     
     
         22 . The method of  claim 21 , further comprising positioning one or more low-pressure equipment at the well site, wherein at least one of the low-pressure equipment has a work zone, wherein the work zone is separate and apart from the red zones for any of the pump banks, and wherein positioning one or more low-pressure equipment comprises disposing the low-pressure equipment so that the corresponding work zone is in proximity to the red zone of one of the pump banks.