Scrubbing debris from a bored well

Abstract

The present disclosure provides methods and compositions for scrubbing debris from a bored well and includes injecting a suspension of acrylonitrile fibers, into the bored well to its open end. The suspension of acrylonitrile fibers scrubs the bored well of loose debris without substantially impeding the drilling capability of the rig by raising the effective liquid viscosity in the bored well. Also provided are pre-measured form factors of the acrylonitrile fibers for convenient and precise preparation of the acrylonitrile fiber suspension at the bored well site.

What is claimed is: 
     
         1 . A method of cleaning unwanted materials from a substantially vertical bored well comprising:
 injecting under pressure a liquid suspension into a conduit inserted into said bored well wherein the conduit and the bored well define an annulus therebetween;   sweeping unwanted materials from the annulus by directing the liquid suspension through the annulus to the unwanted materials;   wherein the liquid suspension comprises acrylonitrile fibers suspended in a liquid.   
     
     
         2 . The method of  claim 1  wherein the acrylonitrile fibers are from about 3 mm to about 12 mm in length. 
     
     
         3 . The method of  claim 1  wherein about 0.5 to about 6.0 lb of acrylonitrile fibers are added per 42 gallons of liquid. 
     
     
         4 . The method of  claim 1  wherein the acrylonitrile fibers are coated with a hydrophilic surfactant. 
     
     
         5 . The method of  claim 1  wherein the acrylonitrile fibers are grafted. 
     
     
         6 . The method of  claim 1  wherein the acrylonitrile fibers include an additive designed to create ultra-violet stability. 
     
     
         7 . The method of  claim 1  wherein the acrylonitrile fibers are formed by co-polymer extrusion. 
     
     
         8 . A method of cleaning loose materials from a bored well, comprising:
 injecting under pressure a liquid suspension into a conduit inserted into the bored well wherein the conduit and the bored well define an annulus therebetween, the bored well being oriented in a substantially non-vertical position; and   sweeping at least a portion of loose materials from the annulus by directing the liquid suspension through the annulus to the materials;   wherein the liquid suspension comprises acrylonitrile fibers suspended in a liquid.   
     
     
         9 . The method of  claim 8  wherein the acrylonitrile fibers are from about 3 mm to about 12 mm in length. 
     
     
         10 . The method of  claim 8  wherein about 0.1 to about 6.0 lb. of acrylonitrile fibers are added per 42 gallons of liquid. 
     
     
         11 . The method of  claim 8  wherein the acrylonitrile fibers are coated with a hydrophilic surfactant. 
     
     
         12 . A pre-measured form factor of acrylonitrile fibers for the convenient and precise charging of proper quantities of acrylonitrile fibers for preparation of liquid suspension for sweeping of at least a portion of loose materials from a bored well, said form factor comprising:
 a pre-measured quantity of acrylonitrile fibers,   wherein said pre-measured quantities are selected from the group consisting of about 0.1 lb, about 0.25 lb, about 0.5 lb, about 1 lb, about 2 lb and about 51 b.   
     
     
         13 . The pre-measured form factor according to  claim 12  further comprising acrylonitrile fiber granules compacted into a tablet or a brick. 
     
     
         14 . The pre-measured form factor according to  claim 12  further comprising loose acrylonitrile granules contained in paper, cardboard or polymer bags or boxes. 
     
     
         15 . The pre-measured form factor according to  claim 12  further comprising acrylonitrile fibers in a liquid pre-mix. 
     
     
         16 . A method of cleaning unwanted materials from a substantially vertical bored well comprising:
 injecting under pressure a liquid suspension into a conduit inserted into said bored well wherein the conduit and the bored well define an annulus therebetween;   sweeping unwanted materials from the annulus by directing the liquid suspension through the annulus to the unwanted materials;   wherein the liquid suspension comprises acrylonitrile fibers suspended in a liquid; and   wherein said liquid suspension was prepared from a pre-measured form factor according to  claim 12 .   
     
     
         17 . A method of cleaning loose materials from a bored well, comprising:
 injecting under pressure a liquid suspension into a conduit inserted into the bored well wherein the conduit and the bored well define an annulus therebetween, the bored well being oriented in a substantially non-vertical position; and   sweeping at least a portion of loose materials from the annulus by directing the liquid suspension through the annulus to the materials;   wherein the liquid suspension comprises acrylonitrile fibers suspended in a liquid; and,   wherein said liquid suspension was prepared from a pre-measured form factor according to  claim 12 .   
     
     
         18 . A method of cleaning unwanted materials from a substantially vertical bored well comprising:
 injecting under pressure a liquid suspension into a conduit inserted into said bored well wherein the conduit and the bored well define an annulus therebetween; and   sweeping unwanted materials from the annulus by directing the liquid suspension through the annulus to the unwanted materials;   wherein the liquid suspension comprises acrylate fibers suspended in a liquid.   
     
     
         19 . The method of  claim 1 , wherein the acrylonitrile fibers are from about 2 mm to about 10 mm in length. 
     
     
         20 . The method of  claim 1 , wherein the acrylonitrile fibers are from about 4 mm to about 10 mm in length. 
     
     
         21 . The method of  claim 1 , wherein the acrylonitrile fibers are from about 5 mm to about 25 mm in length. 
     
     
         22 . The method of  claim 1 , wherein the acrylonitrile fibers are from about 5 mm to about 7 mm in length. 
     
     
         23 . The method of  claim 1 , wherein the acrylonitrile fibers are from about 10 mm to about 15 mm in length.