# US 11,078,748 B2 · Lost circulation shapes

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- Number: US 11,078,748 B2
- Document ID: US11078748B2
- Status: Granted
- Kind: B2
- Application number: 16/268,088
- Filed: 2019-02-05
- Published: 2020-08-06
- Granted: 2021-08-03
- Earliest claimed: 2019-02-05
- Assignees: Saudi Arabian Oil Company
- Applicants: Saudi Arabian Oil Company
- Inventors: Graham Hitchcock
- Web page: https://patentgrep.com/patent/US11078748B2

## CPC

- E21B 33/13: Methods or devices for cementing, for plugging holes, crevices or the like
- C09K 8/516: characterised by their form or by the form of their components, e.g. encapsulated material
- E21B 21/003: {Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138)}
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

Systems and methods for sealing a lost circulation zone associated with a subterranean well include a drill string with a circulating port and a lost circulation material. A lost circulation shape is a hollow body having an outer skin and an open interior chamber. The outer skin includes a plurality of perforations that extend through the outer skin, providing fluid communication between an exterior of the lost circulation shape and the open interior chamber. The plurality of perforations are sized to prohibit a passage of lost circulation material between the exterior of the lost circulation shape and the open interior chamber.

## Claims

### Claim 1

A system for sealing a lost circulation zone associated with a subterranean well, the system including:
a lost circulation material; and
a lost circulation shape, the lost circulation shape being a hollow body having an outer skin and an open interior chamber filled with a drilling fluid, where the outer skin includes a plurality of perforations that extend through the outer skin, providing fluid communication between an exterior of the lost circulation shape and the open interior chamber; where
the lost circulation shape has a minimum size and a maximum size, where: the minimum size of the lost circulation shape is such that a smallest minimum sphere in which the lost circulation shape having the minimum size could fit has a diameter of 5 mm; and the maximum size of the lost circulation shape is such that a smallest maximum sphere in which the lost circulation shape having the maximum size could fit has a diameter of 15 mm; where
at least one of the plurality of perforations is a filling hole, the filling hole sized to provide for filling the open interior chamber with the drilling fluid, where the filling hole has a diameter in a range of 2.5 mm to 5 mm; and
the other of the plurality of perforations are sized to prohibit a passage of lost circulation material between the exterior of the lost circulation shape and the open interior chamber.

### Claim 2 (depends on 1)

The system of claim 1, where the open interior chamber includes a drilling fluid with a drilling fluid density and the lost circulation shape has an average lost circulation shape density, and where a difference between the average lost circulation shape density and the drilling fluid density is 20% or less of the drilling fluid density.

### Claim 3 (depends on 1)

The system of claim 1, where the open interior chamber includes a drilling fluid with a drilling fluid density and the lost circulation shape has an average lost circulation shape density, and where a difference between the average lost circulation shape density and the drilling fluid density is 10% or less of the drilling fluid density.

### Claim 4 (depends on 1)

The system of claim 1, further including a circulating sub and a circulating port that extends through a sidewall of the circulating sub, and the lost circulation shape is sized to flow through the circulating port with a drilling fluid.

### Claim 5 (depends on 1)

The system of claim 1, where the plurality of perforations are sized to trap the lost circulation material within the lost circulation zone for forming a seal within the lost circulation zone.

### Claim 6 (depends on 1)

The system of claim 1, the system further including a drill string having a circulating port, the drill string being located within a wellbore of the subterranean well and defining an annular space between an outer diameter surface of the drill string and an inner diameter surface of the wellbore.

### Claim 7 (depends on 6)

The system of claim 6, where:
the lost circulation material is located within a drilling fluid traveling downhole within the drill string, through the circulating port, and into the annular space; and
the lost circulation shape is located within the drilling fluid travelling downhole within the drill string, through the circulating port, and into the annular space.

### Claim 8 (depends on 1)

The system of claim 1, where the filling hole is sized to provide for filling the open interior chamber with the drilling fluid when the lost circulations shape is subjected to a pressure differential.