Solubilized Polymer Concentrates, Methods of Preparation Thereof, and Well Drilling and Servicing Fluids Containing the Same

Abstract

The invention provides concentrates for reducing the fluid loss on an oil base well drilling or servicing fluid, the concentrates comprising an oleagineous liquid and (1) a polymer which is solublized in the oleagineous liquid, or (2) a polymer which is solublized in the oleaginous liquid together with an organophilic polyphenolic material which is solublized and/or dispersed in the oleagineous liquid. The method of preparing the concentrate and the method of reducing the fluid loss of an oil base well drilling or servicing fluid utilizing the concentrates is also disclosed. The preferred oil soluble polymer is a styrene-butadiene rubber crumb. The preferred oleagineous liquid is an aromatic-free hydrogenated oil essentially containing only saturated hydrocarbons. The preferred polyphenolic material is a source of humic acid, such as mined lignite.

What is claimed is: 
     
         1 . A solubilized polymer concentrate for use in reducing the fluid loss of an oil base well drilling or servicing fluid, the concentrate comprising:
 an oleaginous liquid;   an organophilic polyphenolic material; and   a polymer soluble in the oleaginous liquid,   wherein the concentration of the polymer is from about 0.0168 grams per milliliter (g/mL) of the oleaginous liquid to about 0.0348 g/mL of the oleaginous liquid, and   wherein the particle size of the pre-solubilized polymer is less than about 2000 microns, and wherein the concentration of the organophilic polyphenolic material is from about 0.1677 g/mL of the oleaginous liquid to about 0.3482 g/mL of the oleaginous liquid.   
     
     
         2 . The concentrate of  claim 1 , wherein the polymer is a styrene-butadiene rubber (SBR) crumb or a styrene-butadiene-styrene block copolymer crumb. 
     
     
         3 . The concentrate of  claim 2 , wherein the polymer is a cold-type SBR crumb. 
     
     
         4 . The concentrate of  claim 1 , wherein the oleaginous liquid is an aromatic-free, hydrogenated oil comprising only saturated hydrocarbons of medium- to high-molecular weight. 
     
     
         5 . The concentrate of  claim 1 , wherein the polyphenolic material is selected from the group consisting of lignite, tannin, and mixtures thereof. 
     
     
         6 . The concentrate of  claim 5 , wherein the polyphenolic material is an amine-treated lignite dispersed in an oleaginous liquid in a concentration ranging from 0.17 g/mL of the oleaginous liquid to about 0.35 g/mL of the oleaginous liquid. 
     
     
         7 . A method of manufacturing a solubilized polymer concentrate of  claim 4 , the method comprising:
 admixing the polymer, the organophilic polyphenolic material, and the oleaginous liquid together at a temperature in the range from about 150° F. to about 200° F. for a period of time ranging from about 30 minutes to about 3 hours, at a mixing shear rate of at least 5,000 rpm.   
     
     
         8 . The method of  claim 7 , wherein the oleaginous liquid is an aromatic-free oil containing substantially only saturated hydrocarbons of medium- or high-molecular weight and wherein the polyphenolic material is selected from the group consisting of lignite, tannin, and mixtures thereof. 
     
     
         9 . A method of reducing the fluid loss of an oil base well drilling or servicing fluid, the method of which comprises:
 adding to the fluid the concentrate of  claim 1 ,  2 , or  3 , in an amount sufficient to provide the fluid with from about 0.5 ppb to about 2.5 ppb of the polymer and from about 5 ppb to about 25 ppb of the organophilic polyphenolic material.   
     
     
         10 . A method of reducing the fluid loss of an oil base well drilling or servicing fluid which comprises adding to the fluid the concentrate of  claim 4  in an amount sufficient to provide the fluid with from about 0.5 ppb to about 2.5 ppb of the polymer and from about 5 ppb to about 25 ppb of the organophilic polyphenolic material. 
     
     
         11 . A method of reducing the fluid loss of an oil base well drilling or servicing fluid which comprises adding to the fluid the concentrate of  claim 6  in an amount sufficient to provide the fluid with from about 0.5 ppb to about 2.5 ppb of the polymer and from about 5 ppb to about 25 ppb of the organophilic polyphenolic material. 
     
     
         12 . A method of reducing the fluid loss of an oil base well drilling or servicing fluid which comprises adding to the fluid a concentrate of an oil soluble polymer solublized in an oil wherein the concentration of the polymer is from about 0.03 grams per milliliter of the oil to about 0.143 grams per milliliter of the oil. 
     
     
         13 . The method of  claim 12  wherein the amount of the concentrate is sufficient to provide the fluid with from about 0.5 ppb to about 5.0 ppb of the polymer. 
     
     
         14 . A method of preparing a well treatment fluid, the method comprising:
 providing an oleaginous base fluid;   providing one or more polymer materials having a solubility in the oleaginous base fluid;   providing one or more organophilic polyphenolic materials; and   combining the polymer material and the organophilic polyphenolic material with the base fluid such that the concentration of the oil soluble polymer ranges from about 0.03 g/mL of the base fluid to about 0.143 g/mL of the base fluid.   
     
     
         15 . A method of reducing lost circulation in a subterranean well, the method comprising:
 preparing a treating composition comprising an oleaginous base fluid, a polymer material having a solubility in the oleaginous base fluid, and one or more organophilic polyphenolic materials, the polymer being present in a concentration ranging from about 0.03 g/mL of the base fluid to about 0.143 g/mL of the base fluid;   injecting the treating composition into the well; and   forcing the treating composition into a lost circulation zone within the well.   
     
     
         16 . The method of  claim 15 , wherein the oleaginous base fluid is a hydrocarbon fluid selected from the group consisting of crude oil, diesel oil, kerosene, mineral oil, gasoline, naphtha, toluene, and mixtures thereof. 
     
     
         17 . An oil-field cement composition comprising a cement and the composition of  claim 1 . 
     
     
         18 . A drilling fluid composition comprising a composition according to  claim 1 . 
     
     
         19 . A method of controlling fluid loss properties in oil-field oil-based or invert-based systems, the method comprising adding to the system an effective amount of a composition as defined in  claim 1 .