Method of assessing asphaltene inhibitor efficiency
View Patent ↗Methods of assessing asphaltene inhibitor/dispersant efficiency are disclosed. Also disclosed are methods of assessing solvent/dispersant/cleaner efficacy for remediating asphlatene deposition. The methods are useful in facilitating the production, transportation, storage, and separation of crude oil and natural gas, and more particularly, for preventing the undesired deposition of asphaltene from crude oil.
1. A method of assessing a solvent efficacy for remediating asphaltene deposition, comprising:
submerging a clean coupon into crude oil;
adding a precipitant to the crude oil to promote deposition of asphaltene onto the clean coupon:
removing the coupon from the crude oil;
drying the coupon:
weighing the coupon;
immersing the coupon in a solution comprising at least one solvent, wherein the coupon is immersed for a selected time period, wherein a dispersant is added to the solvent;
removing the coupon from the solution at an end of the selected time period, and drying and weighing the coupon; and
determining % asphaltene deposition removal via equation (2),
%
Removal
=
100
×
(
1
-
Weight
of
asphaltenes
on
coupon
after
immersing
Weight
of
asphaltenes
on
coupon
before
immersing
)
;
(
2
)
assessing the solvent efficacy for remediating asphaltene deposition based on the % asphaltene deposition removal.
2. The method of claim 1 , wherein the dispersant is selected from the group consisting of aliphatic sulphonic acids; alkyl aryl sulphonic acids; aryl sulfonates; lignosulfonates; alkylphenol/aldehyde resins and similar sulfonated resins; polyolefin esters; polyolefin imides; polyolefin esters with alkyl, alkylenephenyl or alkylenepyridyl functional groups; polyolefin amides; polyolefin amides with alkyl, alkylenephenyl or alkylenepyridyl functional groups; polyolefin imides with alkyl, alkylenephenyl or alkylenepyridyl functional groups; alkenyl/vinyl pyrrolidone copolymers; graft polymers of polyolefins with maleic anhydride or vinyl imidazole; hyperbranched polyester amides; polyalkoxylated asphaltenes, amphoteric fatty acids, salts of alkyl succinates, sorbitan monooleate, polyisobutylene succinic anhydride, and any combination thereof.
3. The method of claim 1 , wherein the solvent is an aromatic solvent.
4. The method of claim 1 , wherein the solvent is selected from the group consisting of toluene, xylene, benzene, and heavy aromatic naphtha.
5. The method of claim 1 , wherein the coupon is a glass coupon.
6. The method of claim 1 , wherein the immersing of the coupon is conducted at a pressure of 20,000 psi to 30,000 psi.
7. The method of claim 1 , wherein the coupon is made of synthetic or natural polymer.
8. The method of claim 1 , wherein the solution has a temperature of 80° C. to 300° C.
9. A method of assessing a solvent efficacy for remediating asphaltene deposition, comprising:
submerging a clean coupon into crude oil;
adding a precipitant to the crude oil to promote deposition of asphaltene onto the clean coupon:
removing the coupon from the crude oil;
drying the coupon:
weighing the coupon;
immersing the coupon in a solution comprising at least one solvent, wherein the coupon is immersed for a selected time period, wherein a dispersant is added to the solvent, wherein the solution has a temperature of 300° C.;
removing the coupon from the solution at an end of the selected time period, and drying and weighing the coupon; and
determining % asphaltene deposition removal via equation (2),
%
Removal
=
100
×
(
1
-
Weight
of
asphaltenes
on
coupon
after
immersing
Weight
of
asphaltenes
on
coupon
before
immersing
)
;
(
2
)
assessing the solvent efficacy for remediating asphaltene deposition based on the asphaltene deposition removal.
10. The method of claim 9 , wherein the coupon is a glass coupon.
11. The method of claim 9 , wherein the coupon is a glass coupon or is made of synthetic or natural polymer.