Preserving oil gravity

Abstract

Volatile organics in newly produced oil and gas, and/or condensates and distillates from produced oil and gas, are treated to depress vapor pressure to preserve light hydrocarbons in them when they are in storage vessels. The loss of volatile organics during storage of high gravity oil is minimized by forming a flowable or pumpable gel in the high gravity oil, (and/or condensates and distillates), as they are introduced to a storage vessel. The gel-former may comprise a phosphate ester of one or more low molecular weight alcohols, and a crosslinker including a source of iron or aluminum. Although the gels are flowable and pumpable, they can be broken for transportation from the production site or at another desirable time, returning the hydrocarbon product to its original properties.

1 . Method of inhibiting volatilization of light hydrocarbons from a liquid mixture of hydrocarbons in a storage vessel comprising, (1) prior to placing said liquid mixture of hydrocarbons in said storage vessel, adding to said liquid mixture (a) a phosphorous-containing gel former and (b) a source of polyvalent metal crosslinking agent in an amount effective to form a pumpable gel comprising said liquid mixture of hydrocarbons, and (b) pumping said pumpable gel into said storage vessel. 
     
     
         2 . Method of  claim 1  wherein said liquid mixture of hydrocarbons is a newly produced mixture of hydrocarbons from a producing oil well. 
     
     
         3 . Method of  claim 1  wherein said liquid mixture of hydrocarbons is a newly produced mixture of hydrocarbons from a producing gas well. 
     
     
         4 . Method of  claim 1  wherein said pumpable gel has a Reid vapor pressure in said storage vessel at lest two pounds per square inch lower than said liquid mixture of hydrocarbons would have had without said gel former and said crosslinking agent. 
     
     
         5 . Method of  claim 1  wherein said source of multivalent metal crosslinking agent comprises a source of aluminum. 
     
     
         6 . Method of  claim 3  wherein said mixture of hydrocarbons from a producing gas well comprises condensates from produced gas. 
     
     
         7 . Method of storing and transporting newly produced high gravity oil comprising (a) converting said high gravity oil to a weak gel, (b) placing said weak gel in a storage vessel, (c) storing said weal gel in said storage vessel, (d) breaking said weak gel to render said high gravity oil substantially free of said weak gel, and (e) transporting said high gravity oil to a new location. 
     
     
         8 . Method of  claim 7  wherein said transporting in step (e) is conducted in a pipeline. 
     
     
         9 . Method of  claim 7  wherein said weak gel stored in step (c) has a Reid vapor pressure no greater than 2 psi. 
     
     
         10 . Method of  claim 7  wherein said weak gel is broken in step (d) by adding at least one aminoalcohol in an amount effective to break said weak gel. 
     
     
         11 . Method of storing newly produced high gravity oil to inhibit a reduction in its high gravity by vapor loss comprising (a) adding to said newly produced high gravity oil 0.001 to 0.02 parts by volume phosphate ester of C 2 -C 6  alcohol per cubic meter of high gravity oil, (2) adding to said newly produced high gravity oil containing said phosphate ester 0.001 to 0.02 parts by volume of a crosslinker for said phosphate, thereby forming a pumpable gel, and (c) introducing said newly produced high gravity oil in the form of said pumpable gel to a storage vessel. 
     
     
         12 . Method of  claim 11  wherein said newly produced high gravity oil has a Reid vapor pressure in said storage vessel in step (c) no greater than 2 pounds per square inch. 
     
     
         13 . Method of  claim 11  wherein said high gravity oil has an API gravity of 33° or higher. 
     
     
         14 . Method of  claim 11  wherein said high gravity oil is a condensate from natural gas. 
     
     
         15 . Method of  claim 11  wherein said newly produced high gravity oil flows substantially continuously from a producing well to said storage vessel and the additions of steps (a) and (b) are made into said substantially continuously flowing high gravity oil . 
     
     
         16 . Method of  claim 15  wherein the adding of phosphate ester in step (a) is conducted by adding said phosphate ester to said newly produced high gravity oil as said oil flows from said producing well to said storage vessel. 
     
     
         17 . Method of  claim 16  wherein said adding of said crosslinker of step (b) is conducted after said phosphate is added in step (a) and before said oil reaches said vessel in step (c). 
     
     
         18 . Method of  claim 11  wherein said phosphate ester is predominantly a diester. 
     
     
         19 . Method of  claim 11  wherein said crosslinker contains iron. 
     
     
         20 . Method of  claim 11  wherein said crosslinker includes a nitrogen-containing compound selected from amines, amides, and imidazlines, and an oil selected from animal and vegetable oils.