Early verification of a production well
A method for a rapid verification of satisfactory clean-up at the end of the completion process when starting production of petroleum fluids while the completion rig is still at the well. The method includes marking one or more of separated zones along the well by one or more distinct tracers, before starting production. The tracers are added along with the completion or the clean-up fluid, and the tracers are arranged to be released by relative high concentrations from each zone to an inflowing fluid of oil or gas.
1. An in situ clean-up verification method for use at a well location having a well at an end of a well drilling completion process, when starting production of petroleum fluids while a completion rig is still at the well location, the verification method comprising the following steps:
marking one or more separated zones along the well with one or more distinct tracers before starting the production of petroleum fluids,
wherein said distinct tracers are added along with a completion system,
said distinct tracers are oleophilic,
said distinct tracers are optically detectable, and
said distinct tracers are arranged so that they are released from each separated zone to an inflowing fluid of oil or gas;
starting up the production of petroleum fluids;
collecting at least one sample of a produced petroleum fluid;
processing the at least one sample by a chemical cleavage reaction which introduces water soluble groups to tracer molecule structures to change said distinct tracers into non oleophilic tracers, thereby achieving at least one processed sample,
wherein said non oleophilic tracers are dissolvable in a polar fluid,
transferring said non oleophilic tracers from an oil in the at least one processed sample into an added, polar fluid phase, which is not miscible with an original oil phase of the at least one processed sample; and
optically inspecting the added fluid phase for non oleophilic tracers to verify whether or not all of said non oleophilic tracers occur in the at least one processed sample of the produced petroleum, which thus verifies if inflow of petroleum fluids in said tracer marked separated zones takes place or not, in a start-up phase of the production.
2. The method according to claim 1 , wherein the optical inspection of said non oleophilic tracers is carried out by spectral analysis in UV-light or light in a visible light specter.
3. The method according to claim 1 , wherein detection of said non oleophilic tracers is carried out by the use of fluorescence, photoluminescence, laser induced fluorescence, or diffractive optical elements (DOE).
4. The method according to claim 1 , wherein separation and detection of said non oleophilic tracers are carried out by thin layer chromatography (TLC) and following optical measurements.
5. The method according to claim 1 , wherein separation and detection of said non oleophilic tracers are carried out by chromatography in micro channel flow system and following optical measurements.
6. The method according to claim 1 , wherein said distinct tracers are arranged to be released in high concentrations in a range of 1 ppb to 10 ppm.
7. An in situ clean-up verification method for use at a well location having a well at an end of a well drilling completion process, when starting production of petroleum fluids while a completion rig is still at the well location, the verification method comprising the following steps:
marking one or more separated zones along the well with one or more distinct tracers before starting the production of petroleum fluids,
wherein said distinct tracers are added along with a completion system,
said distinct tracers are oleophilic,
said distinct tracers are optically detectable, and
said distinct tracers are arranged so that they are released from each separated zone to an inflowing fluid of oil or gas;
starting up the production of petroleum fluids;
collecting at least one sample of a produced petroleum fluid;
processing the at least one sample by a phase transfer reaction wherein oleophilic tracers having hydrophobic counter-ions become water soluble by exchanging the hydrophobic counter-ions with hydrophilic counter-ions added through a water-based liquid during extraction to change said distinct tracers into non oleophilic tracers, thereby achieving at least one processed sample,
wherein said non oleophilic tracers are dissolvable in a polar fluid,
transferring said non oleophilic tracers from an oil in the at least one processed sample into an added water based fluid phase; and
optically inspecting the added fluid phase for non oleophilic tracers to verify whether or not all of said non oleophilic tracers occur in the at least one processed sample of the produced petroleum, which thus verifies if inflow of petroleum fluids in said tracer marked separated zones takes place or not, in a start-up phase of the production.
8. The method according to claim 7 , wherein the optical inspection of said non oleophilic tracers is carried out by spectral analysis in UV-light or light in a visible light specter.
9. The method according to claim 7 , wherein detection of said non oleophilic tracers is carried out by the use of fluorescence, photoluminescence, laser induced fluorescence, or diffractive optical elements (DOE).
10. The method according to claim 7 , wherein separation and detection of said non oleophilic tracers are carried out by thin layer chromatography (TLC) and following optical measurements.
11. The method according to claim 7 , wherein separation and detection of said non oleophilic tracers are carried out by chromatography in micro channel flow system and following optical measurements.
12. The method according to claim 7 , wherein said distinct tracers are arranged to be released in high concentrations in a range of 1 ppb to 10 ppm.