Degradable wellbore isolation devices with large flow areas

Patent metadata

Field	Value
Publication number	US-9982506-B2
Application number	US-201414758989-A
Country	US
Kind code	B2
Filing date	Aug 28, 2014
Priority date	Aug 28, 2014
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

An example downhole tool for use in a wellbore lined with casing includes a wellbore isolation device that provides a plurality of components including a mandrel that defines a central flow passage that allows fluid flow in at least one direction through the wellbore isolation device, the wellbore isolation device providing an inner diameter and an outer diameter. A minimum production flow area is provided across the wellbore isolation device and is determined by at least one of: a flow area across the wellbore isolation device that is at least 1/16 a total flow area of the casing at a location of the wellbore isolation device within the wellbore, and a flow area resulting from the inner diameter being at least 25% of the outer diameter. At least the mandrel is made of a slowly degradable material that degrades when exposed to a wellbore environment.

First claim

What is claimed is:

1. A downhole tool for use in a wellbore lined with casing, comprising:
a wellbore isolation device that provides a plurality of components including a mandrel that defines a central flow passage that allows fluid flow in at least one direction through the wellbore isolation device, the wellbore isolation device providing an inner diameter and an outer diameter,
wherein a minimum production flow area is provided across the wellbore isolation device and is determined by at least one of:
a flow area across the wellbore isolation device that is at least 1/16 a total flow area of the casing at a location of the wellbore isolation device within the wellbore; and
a flow area resulting from the inner diameter being at least 25% of the outer diameter,

wherein the inner diameter comprises a diameter of the central flow passage, and the outer diameter comprises a diameter of the wellbore isolation device in an unexpanded configuration, and
wherein at least the mandrel is made of a slowly degradable material that degrades when exposed to a wellbore environment.

2. The downhole tool of claim 1 , wherein the wellbore isolation device is selected from the group consisting of a frac plug, a wellbore packer, a deployable baffle, or any combination thereof.

3. The downhole tool of claim 1 , wherein the flow area across the wellbore isolation device includes any fluid flow area through the central flow passage and through any other flow paths through or around the wellbore isolation device.

4. The downhole tool of claim 3 , wherein the other flow paths comprise at least one flow channel defined longitudinally through the mandrel through which fluids may flow.

5. The downhole tool of claim 1 , wherein the minimum production flow area of the wellbore isolation device is determined by a combination of:
a flow area across the wellbore isolation device that is at least 1/9 of the total flow area of the casing at the location of the wellbore isolation device within the wellbore; and
a flow area resulting from the inner diameter being at least 33% of the outer diameter.

6. The downhole tool of claim 1 , wherein one or more of the plurality of components are made of the slowly degradable material, the plurality of components selected from the group consisting of a frac ball, a slip, a slip wedge, a packer element, a mule shoe, and any combination thereof.

7. The downhole tool of claim 1 , wherein the slowly degradable material comprises a material that exhibits a dissolution rate between 0.01 mg/cm2 per hour and 10 mg/cm2 per hour at a temperature of 200° F. while exposed to a 15% potassium chloride (KCl) solution.

8. The downhole tool of claim 1 , wherein the slowly degradable material comprises a material that loses between 0.1% and 10% of its total mass per day at 200° F. in 3% potassium chloride (KCl) solution.

9. The downhole tool of claim 1 , wherein the degradable material is a galvanically-corrodible metal or metal alloy.

10. The downhole tool of claim 9 , wherein the galvanically-corrodible metal or metal alloy is selected from the group consisting of aluminum, iron, zinc, magnesium, a magnesium alloy, beryllium, and any alloy thereof.

11. The downhole tool of claim 10 , wherein the magnesium alloy includes magnesium at a concentration in a range of about 70% to about 98%.

12. The downhole tool of claim 10 , wherein the magnesium alloy includes magnesium and a metal selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, calcium, strontium, barium, aluminum, gallium, indium, tin, thallium, lead, bismuth, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, praseodymium, silver, lanthanum, hafnium, tantalum, tungsten, terbium, rhenium, osmium, iridium, platinum, gold, neodymium, gadolinium, erbium, oxides of any of the foregoing, and any combinations thereof.

13. The downhole tool of claim 10 , wherein the magnesium alloy includes magnesium and a non-metal selected from the group consisting of graphite, carbon, silicon, boron nitride, and any combinations thereof.

14. The downhole tool of claim 10 , wherein the magnesium alloy is selected from the group consisting of:
4.8% to 6.2% zinc, a minimum 0.45% zirconium, up to 0.3% impurities, and balance magnesium;
7.8% to 9.2% aluminum, 0.2% to 0.8% zinc, 0.12% manganese, up to 0.015% impurities, and balance magnesium;
2.5% to 3.5% aluminum, 0.7% to 1.3% zinc, 0.2% manganese, up to 0.15% impurities, and balance magnesium; and
any combinations thereof.

15. The downhole tool of claim 1 , wherein the wellbore isolation device exhibits a density selected from the group consisting of:
a density that is less than 2 g/cm3 when the slowly degradable material is a magnesium alloy;
a density that is less than 3 g/cm3 when the slowly degradable material is magnesium or an aluminum alloy;
a density that is less than 5 g/cm3 when the slowly degradable material is a material that is lighter than steel;
and any combinations thereof.

16. The downhole tool of claim 1 , further comprising a sheath disposed on all or a portion of at least one of the plurality of components, the sheath comprising a material selected from the group consisting of a TEFLON® coating, a wax, a drying oil, a polyurethane, an epoxy, a crosslinked partially hydrolyzed polyacrylic, a silicate material, a glass, an inorganic durable material, a polymer, polylactic acid, polyvinyl alcohol, polyvinylidene chloride, a hydrophobic coating, paint, and any combination thereof.

17. A method, comprising:
introducing a wellbore isolation device into a wellbore lined at least partially with casing, the wellbore isolation device providing a plurality of components including a mandrel that defines a central flow passage that allows fluid flow in at least one direction through the wellbore isolation device, wherein at least the mandrel is made of a slowly degradable material;
anchoring the wellbore isolation device within the casing at a target location, the wellbore isolation device providing an inner diameter and an outer diameter;
performing at least one downhole operation;
degrading at least the mandrel upon exposing the wellbore isolation device to a wellbore environment; and
commencing production operations within the wellbore, wherein a minimum production flow area is provided across the wellbore isolation device and is determined by at least one of:
a flow area across the wellbore isolation device that is at least 1/16 a total flow area of the casing at a location of the wellbore isolation device within the wellbore; and
a flow area resulting from the inner diameter being at least 25% of the outer diameter.

18. The method of claim 17 , wherein the wellbore isolation device is selected from the group consisting of a frac plug, a wellbore packer, a deployable baffle, or any combination thereof.

19. The method of claim 17 , wherein the minimum production flow area of the wellbore isolation device is determined by a combination of:
a flow area across the wellbore isolation device that is at least 1/9 of the total flow area of the casing at the location of the wellbore isolation device within the wellbore; and
a flow area resulting from the inner diameter being at least 33% of the outer diameter.

20. The method of claim 17 , wherein one or more of the plurality of components are made of the slowly degradable material, the method further comprising degradi

Assignees

• Halliburton Energy Services Inc

Inventors

• Walton Zachary
• Fripp Michael Linley
• Jurgensmeier Michael James
• Murphree Zachary

Classifications

• C09K8/428

  for squeeze cementing, e.g. for repairing · CPC title

• E21B33/1293 Primary

  with means for anchoring against downward and upward movement (E21B33/1291, E21B33/1295 take precedence) · CPC title

• E21B33/1294

  characterised by a valve, e.g. a by-pass valve · CPC title

• E21B43/26

  by forming crevices or fractures · CPC title

• E21B33/13

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title