Methods of treating subterranean formations using low-molecular-weight fluids

Abstract

The present invention relates to systems and methods useful in subterranean treatment operations. More particularly, the present invention relates to systems and methods for treating subterranean formations using low-molecular-weight fluids. Examples of methods of the present invention include methods for fracturing a portion of a subterranean formation penetrated by a well bore; methods of enhancing production from multiple subterranean formations penetrated by a well bore during a single trip through the well bore; methods of enhancing production, in real time, from multiple subterranean formations penetrated by a well bore during a single trip through the well bore; and methods of reducing the cost of enhancing production from multiple subterranean formations penetrated by a well bore by stimulating multiple formations, on a single trip through the well bore, with a fluid that minimizes damage to the formation.

1 - 49 . (canceled)  
     
     
         50 . A method of enhancing production from multiple subterranean formations penetrated by a well bore during a single trip though the well bore, comprising: 
 inserting a tool assembly into the well bore adjacent a desired location in a formation;    placing a low-molecular-weight fluid into the formation so as to create or enhance at least one fracture in the formation;    relocating the tool assembly within the well bore adjacent another desired location in the same, or different formation; and    repeating the step of placing a low-molecular-weight fluid into the formation so as to create or enhance at least one fracture in the formation.    
     
     
         51 . The method of  claim 50  wherein the well bore comprises a casing disposed therein, further comprising: 
 passing a fluid that comprises an abrasive particulate material to the tool assembly; and    discharging the fluid that comprises an abrasive particulate material from the tool assembly towards the casing to form perforations in the casing and to permit the flow of the low-molecular-weight fluid through the casing.    
     
     
         52 . The method of  claim 51  wherein the tool assembly comprises a sub, and wherein the step of passing the fluid that comprises an abrasive particulate material comprises introducing the fluid that comprises an abrasive particulate material to the sub, wherein the fluid that comprises an abrasive particulate material is discharged from the sub towards the casing.  
     
     
         53 . The method of  claim 51  wherein the fluid that comprises an abrasive particulate material is a low-molecular-weight fluid.  
     
     
         54 . The method of  claim 50  wherein the low-molecular-weight fluid enhances the regain permeability of the formation.  
     
     
         55 . The method of  claim 50  wherein the low-molecular-weight fluid has an average molecular weight in the range of from about 100,000 to about 250,000.  
     
     
         56 . The method of  claim 50  wherein the low-molecular-weight fluid has a viscosity of at least about 2 cP, where the viscosity is measured at about 25° C.  
     
     
         57 . The method of  claim 50  wherein the low-molecular-weight fluid comprises an acid system.  
     
     
         58 . The method of  claim 57  wherein the acid system comprises a viscosifier.  
     
     
         59 . The method of  claim 57  wherein the acid system comprises a hydrochloric acid based delayed carbonate acid system or a hydrofluoric acid based delayed carbonate acid system.  
     
     
         60 . The method of  claim 50  wherein the low-molecular-weight fluid comprises water.  
     
     
         61 . The method of  claim 50  wherein the low-molecular-weight fluid comprises water, a substantially fully hydrated depolymerized polymer, and a crosslinking agent.  
     
     
         62 . The method of  claim 61  wherein the substantially fully hydrated depolymerized polymer is a depolymerized polysaccharide.  
     
     
         63 . The method of  claim 61  wherein the substantially fully hydrated depolymerized polymer is selected from the group consisting of hydroxypropylguar, carboxymethylhydroxypropylguar, carboxymethylguar, hydroxyethylguar, and carboxymethylhydroxyethylguar.  
     
     
         64 . The method of  claim 61  wherein the substantially fully hydrated depolymerized polymer is present in the low-molecular-weight fluid in an amount in the range of from about 0.2% to about 5% by weight of the water therein.  
     
     
         65 . A method of enhancing production from multiple subterranean formations penetrated by a well bore comprising a casing during a single trip through the well bore, comprising: 
 inserting a tool assembly into the casing adjacent a desired location in a formation;    forming openings in the casing at the desired location;    passing a low-molecular-weight fluid through the openings into the formation so as to create or enhance at least one fracture in the formation;    relocating the tool assembly within the casing to another desired location in the same, or different, formation; and    repeating the steps of forming openings in the casing and passing the low-molecular-weight fluid through the openings into the formation so as to create or enhance at least one fracture in the formation.    
     
     
         66 . The method of  claim 65  wherein the step of forming openings in the casing at the desired location comprises: 
 passing a fluid that comprises an abrasive particulate material to the tool assembly; and    discharging the fluid that comprises an abrasive particulate material from the tool assembly towards the casing to form perforations in the casing and to permit theflaw of the low-molecular-weight fluid through the casing.    
     
     
         67 . The method of  claim 66  wherein the tool assembly comprises a sub, and wherein the step of passing the fluid that comprises an abrasive particulate material comprises introducing the fluid that comprises an abrasive particulate material to the sub, wherein the fluid that comprises an abrasive particulate material is discharged from the sub towards the casing.  
     
     
         68 . The method of  claim 66  wherein the fluid that comprises an abrasive particulate material is a low-molecular-weight fluid.  
     
     
         69 . The method of  claim 65  wherein the low-molecular-weight fluid enhances the regain permeability of the formation.  
     
     
         70 . The method of  claim 65  wherein the low-molecular-weight fluid has an average molecular weight in the range of from about 100,000 to about 250,000.  
     
     
         71 . The method of  claim 65  wherein the low-molecular-weight fluid has a viscosity of at least about 2 cP, where the viscosity is measured at about 25° C.  
     
     
         72 . The method of  claim 65  wherein the low-molecular-weight fluid comprises an acid system.  
     
     
         73 . The method of  claim 72  wherein the acid system comprises a viscosifier.  
     
     
         74 . The method of  claim 72  wherein the acid system comprises a hydrochloric acid based delayed carbonate acid system or a hydrofluoric acid based delayed carbonate acid system.  
     
     
         75 . The method of  claim 65  wherein the low-molecular-weight fluid comprises water.  
     
     
         76 . The method of  claim 65  wherein the low-molecular-weight fluid comprises water, a substantially fully hydrated depolymerized polymer, and a crosslinking agent.  
     
     
         77 . The method of  claim 76  wherein the substantially fully hydrated depolymerized polymer is a depolymerized polysaceharide.  
     
     
         78 . The method of  claim 76  wherein the substantially fully hydrated depolymerized polymer is selected from the group consisting of hydroxypropylguar, carboxymethylhydroxypropylguar, carboxymethylguar, hydroxyethylguar, and carboxymethylhydroxyethylguar.  
     
     
         79 . The method of  claim 76  wherein the substantially fully hydrated depolymerized polymer is present in the low-molecular-weight fluid in an amount in the range of from about 0.2% to about 5% by weight of the water therein.  
     
     
         80 - 100 . (canceled)  
     
     
         101 . A method of reducing the cost of enhancing production from multiple formations penetrated by a well bore by stimulating multiple formations, on a single trip through the well bore, with a fluid that minimizes damage to the formation, comprising: 
 inserting a tool assembly into the well bore adjacent a desired location in a formation;    placing a low-molecular-weight fluid into the formation so as to create or enhance at least one fracture in the formation;    relocating the tool assembly within the well bore to another desired location in the same, or different, formation; and    repeating the step of placing a low-molecular-weight fluid into the formation so as to create or enhance at least one fracture in the formation;    wherein the low-molecular-weight fluid enhances the regain permeability of the formation.    
     
     
         102 . The method of  claim 101  wherein the well bore comprises a casing disposed therein, further comprising: 
 passing a fluid that comprises an abrasive particulate material to the tool assembly; and    discharging the fluid that comprises an abrasive particulate material from the tool assembly towards the casing to form perforations in the casing and to permit the flow of the low-molecular-weight fluid through the casing.    
     
     
         103 . The method of  claim 102  wherein the tool assembly comprises a sub, and wherein the step of passing the fluid that comprises an abrasive particulate material comprises introducing the fluid that comprises an abrasive particulate material to the sub, wherein the fluid that comprises an abrasive particulate material is discharged from the sub towards the casing.  
     
     
         104 . The method of  claim 102  wherein the fluid that comprises an abrasive particulate material is a low-molecular-weight fluid.  
     
     
         105 . The method of  claim 101  wherein the low-molecular-weight fluid has an average molecular weight in the range of from about 100,000 to about 250,000.  
     
     
         106 . The method of  claim 101  wherein the low-molecular-weight fluid has a viscosity of at least about 2 6Th where the viscosity is measured at about 250 C.  
     
     
         107 . The method of  claim 101  wherein the low-molecular-weight fluid comprises an acid system.  
     
     
         108 . The method of  claim 107  wherein the acid system comprises a viscosifier.  
     
     
         109 . The method of  claim 107  wherein the acid system comprises a hydrochloric acid based delayed carbonate acid system or a hydrofluoric acid based delayed carbonate acid system.  
     
     
         110 . The method of  claim 101  wherein the low-molecular-weight fluid comprises water.  
     
     
         111 . The method of  claim 101  wherein the low-molecular-weight fluid comprises water, a substantially fully hydrated depolymerized polymer, and a crosslinking agent.  
     
     
         112 . The method of  claim 111  wherein the substantially fully hydrated depolymerized polymer is a depolymerized polysaccharide.  
     
     
         113 . The method of  claim 111  wherein the substantially fully hydrated depolymerized polymer is selected from the group consisting of hydroxypropylguar, carboxymethylhydroxypropylguar, carboxymethylguar, hydroxyethylguar, and carboxymethylhydroxyethylguar.  
     
     
         114 . The method of  claim 111  wherein the substantially fully hydrated depolymerized polymer is present in the low-molecular-weight fluid in an amount in the range of from about 0.2% to about 5% by weight of the water therein.