Temperature actuated drop balls and methods and systems for use thereof

Abstract

Disclosed are devices, systems and methods for actuating tools in a well in a reservoir, such as sliding sleeves used to direct fracturing fluid into the reservoir. The sleeves are actuated using drop balls that seat in the tool with sufficient force to cause the sleeve to move. The drop balls are made from a frangible material having a compressed or deformed shape memory alloy component therewithin. After the drop balls have actuated the sleeves in the well, they are exposed to a temperature change from below to above the transition temperature of the shape memory alloy such that the component expands and the frangible material fragments into pieces, such that the pieces allow unobstructed fluid flow in the well. Optionally, a heating element can be used to effect the temperature change.

What is claimed is: 
     
         1 . A drop ball for actuating tools in a well in a reservoir, comprising:
 a ball comprising a frangible material having a generally spherical shape and a diameter of from 0.5 to 5 inches for dropping in the well to actuate a tool wherein the drop ball seats in the tool with applied pressure thereby actuating the tool; and   at least one component comprising a shape memory alloy material located within the frangible material of the ball wherein the shape memory alloy material has a transition temperature of from −60 to 400° F. and wherein the at least one component is compressed or deformed from an original shape of the at least one component;   wherein upon exposing the ball to a change in temperature from below the transition temperature to above the transition temperature, the at least one component expands or transforms to its original shape thereby causing the frangible material of the ball to fragment into pieces, such that the pieces allow unobstructed fluid flow in the well.   
     
     
         2 . The drop ball of  claim 1  wherein the at least one component has a volume within the ball of from 2 to 50% of the volume of the ball. 
     
     
         3 . The drop ball of  claim 1  wherein the at least one component has a volume within the ball of from 10 to 30% of the volume of the ball. 
     
     
         4 . The drop ball of  claim 1  wherein the frangible material is selected from the group consisting of powdered metal, glass, ceramic material, cast material, brittle polymeric material and combinations thereof. 
     
     
         5 . The drop ball of  claim 1  wherein the frangible material is soluble in production fluids containing hydrocarbons and/or brine at pressure and temperature conditions in the well. 
     
     
         6 . The drop ball of  claim 1  wherein the shape memory alloy material is selected from the group consisting of nickel-titanium (NiTi), copper-aluminum-nickel, copper-zinc-aluminum, manganese-copper, iron-manganese-silicon or other shape memory alloys created by alloying zinc, copper, iron or gold, and combinations thereof. 
     
     
         7 . The drop ball of  claim 1  wherein the transition temperature of the shape memory alloy material is from 150 to 350° F. 
     
     
         8 . The drop ball of  claim 1  wherein the at least one component has a shape selected from the group consisting of a straight-edged shape, a curved-edged shape, a pellet shape, a wire shape, a plug shape, a bent shape, a coil shape and combinations thereof. 
     
     
         9 . The drop ball of  claim 1  wherein the at least one component is in the form of multiple pieces of shape memory alloy material dispersed within the frangible material. 
     
     
         10 . The drop ball of  claim 1  further comprising a heating element located in the ball for heating the at least one component to effect the change in temperature from below the transition temperature to above the transition temperature. 
     
     
         11 . The drop ball of  claim 10  wherein the heating element is connected to a programmable time delay. 
     
     
         12 . The drop ball of  claim 1  wherein the tools are sleeves in a well to direct fracturing fluid into the reservoir. 
     
     
         13 . The drop ball of  claim 1  wherein the ball is capable of withstanding a pressure of at least 5,000 psi. 
     
     
         14 . A method for actuating tools in a well in a reservoir, comprising:
 dropping the drop ball of  claim 1  in the well to actuate a tool wherein the ball seats in the tool with applied pressure thereby actuating the tool;   wherein the transition temperature is in a range of a static reservoir temperature and an expected cool-down temperature during the fracturing treatment;   wherein the temperature of the well remains below the transition temperature during flow of fracturing fluids and exceeds the transition temperature after cessation of flow of fracturing fluids, such that the at least one component of the drop ball expands thereby causing the frangible material of the drop ball to fragment into pieces, such that the pieces allow unobstructed fluid flow in the well.   
     
     
         15 . The method of  claim 14  wherein the expanding at least one component creates cracks to increase surface area exposure of the pieces to production fluids and speed dissolution of the pieces. 
     
     
         16 . The method of  claim 14  further comprising effecting the change in temperature from below the transition temperature to above the transition temperature using a heating element located in the drop ball for heating the at least one component. 
     
     
         17 . The method of  claim 16  wherein the heating element is connected to a battery and programmable chip comprising a programmed time delay for connecting the battery to the heating element after a predetermined amount of time for controlling the operation of the heating element. 
     
     
         18 . The method of  claim 14  wherein the tools are sleeves in the well to direct fracturing fluid into the reservoir. 
     
     
         19 . A system for actuating tools in a well in a reservoir, comprising:
 a. the drop ball of  claim 1  for dropping in the well to actuate a tool wherein the drop ball seats in the tool with applied pressure thereby actuating the tool;   b. a heating element connected to the drop ball for effecting the change in temperature from below the transition temperature to above the transition temperature;   c. a battery for powering the heating element; and   d. a programmable chip comprising a programmed time delay for connecting the battery to the heating element after a predetermined amount of time for controlling the operation of the heating element, such that the component of the drop ball is heated thereby exposing the ball to the change in temperature from below the transition temperature to above the transition temperature, and the at least one component expands or transforms to its original shape thereby causing the frangible material of the drop ball to fragment into pieces, such that the pieces allow unobstructed fluid flow in the well.   
     
     
         20 . The system of  claim 19  wherein the programmable chip is programmed at a surface location. 
     
     
         21 . The system of  claim 19  wherein the predetermined amount of time is from 1 hour to 300 hours. 
     
     
         22 . The system of  claim 19  wherein the tools are sleeves in the well to direct fracturing fluid into the reservoir.