Continuous Slow Dissolving Chemical Treatment for Oil and Gas Wells

Abstract

The invention relates to dispensing slow release chemicals for inhibiting the formation of scale, corrosion or other precipitates in hydrocarbon wells. The chemical is provided into a dispenser positioned for at least nearly continuous exposure to liquid preferably in the active water phase. The active water phase is generally just below the inlet into production tubing.

1 . A method for slow release dispensing of a chemical within a producing hydrocarbon well to control a chemical process such as corrosion or hydrate formation or alter the physical properties of one or more chemicals such as dissolving paraffin waxes, where the method comprises:
 a) selecting a chemical for obtaining a chemical result within the wellbore where the chemical is bound within a complex so that it slowly dissolves in wellbore fluids of the type existing in a producing hydrocarbon well and is slowly dispensed over time;   b) installing a chemical dispenser into the hydrocarbon well such that the chemical dispenser is substantially continuously exposed to such liquids in the hydrocarbon well and wherein the dispenser includes an enclosure with a perforated portion for fluids to pass through and contact and dissolve the chemical; and   c) continuously dispensing the chemical from the dispenser into the liquids in the hydrocarbon wellbore to maintain an effective dosage of the chemical in the liquid to obtain the desired chemical result.   
     
     
         2 . The method for slow release dispensing of a chemical within a producing hydrocarbon well according to  claim 1  wherein the well includes a producing zone and the dispenser is attached to the periphery of production tubing prior to installing the production tubing into the hydrocarbon well such that when the production tubing is installed in the well, the chemical dispenser is positioned below the producing zone and wherein the dispenser includes an open upper portion and a porous bottom surface for fluids to pass through and further including a step of installing the chemical into the dispenser by depositing the chemical from the surface into the dispenser that is positioned below the producing zone. 
     
     
         3 . The method for slow release dispensing of a chemical within a producing zone of a hydrocarbon wellbore according to  claim 1  wherein the chemical is installed into the dispenser prior to the step of installing the dispenser into in the hydrocarbon well. 
     
     
         4 . The method for slow release dispensing of a chemical within a producing zone of a hydrocarbon wellbore according to  claim 3  wherein the dispenser comprises a tube with a sidewall and perforations in at least portions of the side wall and the chemical is installed into the tube prior to the step of installing the hydrocarbon production equipment in the hydrocarbon wellbore. 
     
     
         5 . The method for slow release dispensing of a chemical within a producing hydrocarbon wellbore according to  claim 1  where in the step of installing the dispenser into the hydrocarbon well further includes a step of attaching the dispenser to hydrocarbon production equipment wherein the hydrocarbon production equipment has a bottom end that when installed into the well is spaced from the bottom of the well to define a rathole between the bottom end of the hydrocarbon production equipment and the bottom of the well, and wherein the dispenser is attached near the bottom end of the hydrocarbon production equipment to extend into the rathole and slowly dispense the chemical. 
     
     
         6 . The method for slow release dispensing of a chemical within a producing hydrocarbon wellbore according to  claim 5  wherein the method includes installing the chemical dispenser at the end of an extension so that the chemical dispenser is fully immersed in liquid in the wellbore. 
     
     
         7 . The method for slow release dispensing of a chemical within a producing hydrocarbon wellbore according to  claim 1  wherein the selected chemical causes inhibition of scale within the well. 
     
     
         8 . The method for slow release dispensing of a chemical within a producing hydrocarbon wellbore according to  claim 1  wherein the selected chemical causes inhibition of corrosion within the well. 
     
     
         9 . A method for slow release dispensing of a chemical within a producing hydrocarbon wellbore to control a chemical process such as corrosion or hydrate formation or alter the physical properties of one or more chemicals such as dissolving paraffin waxes, where the method comprises:
 a) selecting a chemical for obtaining a chemical result within the wellbore where the chemical is bound within a complex so that it slowly dissolves in wellbore fluids of the type existing in a hydrocarbon wellbore and is slowly dispensed over time;   b) attaching the chemical dispenser onto hydrocarbon production equipment;   c) installing the hydrocarbon production equipment into the hydrocarbon wellbore such that the chemical dispenser is substantially continuously exposed to such liquids in a hydrocarbon wellbore;   d) installing the chemical into the dispenser; and   e) continuously dispensing the chemical from the dispenser into the liquids in the hydrocarbon wellbore to maintain an effective dosage of chemical in the liquid to obtain the desired chemical result.   
     
     
         10 . The method for slow release dispensing of a chemical according to  claim 9  wherein the step of installing the chemical into the dispenser occurs after the hydrocarbon production equipment is installed into the wellbore. 
     
     
         11 . The method for slow release dispensing of a chemical according to  claim 9  wherein the step of installing the chemical into the dispenser occurs before the hydrocarbon production equipment is installed into the wellbore.