CPC E21B 29/02 (2013.01) [C06B 45/18 (2013.01); C06B 45/32 (2013.01); E21B 31/002 (2013.01); E21B 33/12 (2013.01); Y10T 428/12729 (2015.01); Y10T 428/31605 (2015.04); Y10T 428/31692 (2015.04)] | 9 Claims |
1. A method for controlling the dissolving, degrading, reacting, and/or fracturing of a component for use in down-hole applications comprising:
a. providing a down-hole component for use in down-hole applications; said down-hole component is selected from the group consisting of a frac ball, a valve, a plug, a ball, a sleeve, a casing, a hydraulic actuating tool, a ball/ball seat assembly, a fracture plug, sealing elements, and a well drilling tool; said down-hole component at least partially formed of a reactive component; said reactive component includes:
i. a core; at least 70 wt. % of said core including a core material that includes a cast magnesium alloy; said cast magnesium all includes greater than 50 wt. % magnesium and one or more metals selected from the group consisting of aluminum, calcium, lithium, manganese, rare earth metal, silicon, SiC, yttrium, and zirconium; said cast metal alloy has a dissolution rate of 0.1-100 mm/hr. at 100-300° F. in water or salt water; and,
ii. a surface layer partially or fully encapsulatings said core; said surface layer having a different composition from said core; said surface layer includes one or more materials selected from the group consisting of a) zinc, b) zinc alloy, and c) silicon-containing compound; said surface layer formulated to be insoluble in said down-hole fluid environment until exposed to a chemical modification agent, a certain pH and/or a certain temperature; said surface layer forming a protective layer about said core to inhibit or prevent said core from degrading, dissolving, and/or reacting when said down-hole component is exposed to said down-hole fluid environment in said down-hole applications;
b. inserting said down-hole component into a well; said surface layer of said reactive component not or substantially not dissolving, degrading, and/or reacting in said down-hole fluid environment in said well; and,
c. exposing said surface layer of said reactive component to said chemical modification agent, said certain pH and/or said certain temperature to cause said surface layer to degrade, dissolve, and/or react to thereby expose at least a portion of said core to said down-hole fluid environment; said down-hole component at least partially degrading, dissolving, reacting, and/or fracturing after said core is exposed to said down-hole fluid environment.
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