Degradation of Polylactide in a Well Treatment

Abstract

Methods of treating a portion of a well include the steps of: (A) depositing a solid particulate into the portion of the well, wherein the solid particulate comprises an aliphatic polyester, preferably a polylactide; and (B) contacting the particulate deposited in the portion of the well with a treatment fluid comprising: (i) water; (ii) a source of a strong alkali; and (iii) a source of a strong oxidizer. The steps of depositing and contacting can be with a single treatment fluid or separate treatment fluids.

What is claimed is: 
     
         1 . A method of treating a portion of a well, the method comprising the step of:
 introducing a treatment fluid into the portion of the well, wherein the treatment fluid comprises: (i) a solid particulate, wherein the solid particulate is deposited in the well, and wherein the solid particulate comprises an aliphatic polyester; (ii) water; (iii) a source of a strong alkali; and (iv) a source of a strong oxidizer.   
     
     
         2 . The method according to  claim 1 , wherein the aliphatic polyester is a polylactide. 
     
     
         3 . The method according to  claim 1 , wherein the solid particulate consists essentially of one or more polylactides. 
     
     
         4 . The method according to  claim 1 , wherein the solid particulate has a particulate size distribution anywhere between the range of about 0.005 millimeter to about 5 millimeter. 
     
     
         5 . The method according to  claim 1 , wherein the step of introducing the treatment fluid forms a filtercake in the portion of the well, wherein the filtercake comprises the solid particulate. 
     
     
         6 . The method according to  claim 1 , wherein the treatment fluid comprises a continuous liquid phase that is water-based. 
     
     
         7 . The method according to  claim 6 , wherein the treatment fluid additionally comprises: a viscosity-increasing agent. 
     
     
         8 . The method according to  claim 7 , wherein the treatment fluid additionally comprises: a crosslinker for the viscosity-increasing agent. 
     
     
         9 . The method according to  claim 1 , wherein the source of the strong alkali is in the range of about 1% to about 20% by weight of the water of the treatment fluid. 
     
     
         10 . The method according to  claim 1 , wherein the source of the strong alkali is selected from the group consisting of: an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkaline earth oxide, and any combination thereof. 
     
     
         11 . The method according to  claim 1 , wherein the source of the strong oxidizer is in the range of about 0.5% to about 15% by weight of the water of the treatment fluid. 
     
     
         12 . The method according to  claim 1 , wherein the source of the strong oxidizer is selected from the group consisting of: chemicals that can release or that contain hydrogen peroxide, chemicals that can release or contain chlorite, and any combination thereof. 
     
     
         13 . The method according to  claim 1 , wherein a design temperature in the portion of well during the method of treating is at most about 93° C. (200° F.). 
     
     
         14 . The method according to  claim 13 , further comprising the step of beginning to flow back a downhole fluid from the portion of the well within about 1 hour of the step of introducing the treatment fluid into the portion of the well. 
     
     
         15 . A method of treating a portion of a well, the method comprising the steps of:
 (A) introducing a first treatment fluid into the portion of the well, wherein the first treatment fluid comprises a solid particulate, wherein the solid particulate is deposited in the well, and wherein the solid particulate comprises an aliphatic polyester; and   (B) before or after the step of introducing the first treatment fluid into the portion of the well, introducing a second treatment fluid into the portion of the well, whereby the second treatment fluid contacts the solid particulate in the portion of the well, and wherein the second treatment fluid comprises: (i) water; (ii) a source of a strong alkali; and (iii) a source of a strong oxidizer.   
     
     
         16 . The method according to  claim 15 , wherein the first treatment fluid comprises a continuous liquid phase that is water-based. 
     
     
         17 . The method according to  claim 16 , wherein the first treatment fluid additionally comprises: a viscosity-increasing agent. 
     
     
         18 . The method according to  claim 15 , wherein a design temperature in the portion of well during the method of treating is at most about 93° C. (200° F.). 
     
     
         19 . The method according to  claim 18 , further comprising the step of beginning to flow back a downhole fluid from the portion of the well within about 1 hour of the later of the steps of introducing the first treatment fluid or the step of introducing the second treatment fluid into the portion of the well.