Automatic dosing of surfactant for recovered hydrocarbon enhancement

A method comprising:

• producing a bulk fluid from a subterranean formation, the bulk fluid comprising at least water and a hydrocarbon, and having constituent parameters selected from the group consisting of salinity (S), water volume (Wp), hydrocarbon concentration (x), equivalent alkane carbon number (EACN), surfactant concentration y, and ionic surfactant characteristic curvature (Cc) or nonionic surfactant characteristic curvature (Ccn);
• sampling the bulk fluid produced from the subterranean formation, thereby forming at least one sampled fluid;
• manipulating the sampled fluid by adding at least one of a known component selected from the group consisting of added surfactant, added hydrocarbon, added salt, added water, and any combination thereof;
• determining at least one of the constituent parameters of the manipulated sampled fluid in combination with a surfactant composition based on obtaining a hydrophilic-lipophilic deviation (HLD) substantially equal to 0;
• determining at least two additional constituent parameters of the sampled fluid, such as V (volume of the sampled fluid);
• Saj,i (amount of any added salt);
• Waj,i (volume of any added water);
• xaj,i (volume of any added hydrocarbon);
• EACNj,i (EACN of any added hydrocarbon);
• ya3,i (volume of any added surfactant);
• Ccj.i (characteristic curvature of any added surfactant where the surfactant is ionic);
• and Ccnj.i (characteristic curvature of any added surfactant where the surfactant is nonionic);
• identifying a type and concentration of separating surfactant to include in the bulk fluid where HLD is substantially equal to 0;
• scaling the identified type and concentration of the separating surfactant to a volume of the sampled fluid, introducing the scaled identified type and concentration of the separating surfactant into the sampled fluid, and observing a morphological phase distribution of the sample fluid, wherein an oil-water separation morphological phase distribution is equivalent to the HLD being substantially equal to 0;
• and
• introducing the identified type and concentration of the separating surfactant into the bulk fluid.

A system comprising:

• a main tubular coupled to a pump and extending from a surface into a subterranean formation,
• wherein produced bulk fluid is pumped to the surface from the subterranean formation, and
• wherein the bulk fluid comprises at least water and a hydrocarbon, and has constituent parameters selected from the group consisting of salinity (S), water volume (Wp), hydrocarbon concentration (x), equivalent alkane carbon number (EACN), surfactant concentration y, and ionic surfactant characteristic curvature (Cc) or nonionic surfactant characteristic curvature (Ccn);
• a storage container for retaining the bulk fluid;
• a sampling tubular in fluid communication with the main tubular for sampling the bulk fluid produced from the subterranean formation, thereby forming at least one sampled fluid;
• and
• a dosing system coupled to the sampling tubular and configured to receive the at least one sampled fluid, the dosing system configured to determine at least one constituent parameter of the sampled fluid, identify a type and concentration of separating surfactant to include in the bulk fluid to obtain a hydrophilic-lipophilic deviation (HLD) substantially equal to 0, and introduce the identified type and concentration of the separating surfactant into the storage container retaining the bulk fluid.