Placement of stabilizers, standoffs, and rollers on a downhole tool string

Patent metadata

Field	Value
Publication number	US-10125545-B2
Application number	US-201514975694-A
Country	US
Kind code	B2
Filing date	Dec 18, 2015
Priority date	Dec 18, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A manufacturing system that manufactures a downhole tool string, which includes a model that describes relationship between properties of the downhole tool string, properties of a borehole, properties of a formation, and properties of a mud cake formed on a surface of the borehole and a design device that iteratively determines contact parameters that describe one or more contact points expected between the downhole tool string and the mud cake based at least in part on the model, in which the contact parameters comprise contact force expected at each of the contact points, adjusts the properties of the downhole tool string to add a spacer at one of the contact points associated with highest contact force, and indicates location, type, or both of the spacer to enable the manufacturing system to attach the spacer to the downhole tool string before deployment of the downhole tool string in the borehole.

First claim

What is claimed is:

1. A manufacturing system used to manufacture a downhole tool string configured to be deployed in a borehole formed in a sub-surface formation, comprising:
a model configured to describe relationship between properties of the downhole tool string, properties of the borehole, properties of the sub-surface formation, and properties of mud cake formed on a surface of the borehole; and
a design device configured to:
iteratively determine contact parameters that describe one or more contact points expected between the downhole tool string and the mud cake based at least in part on the model, wherein the contact parameters comprise contact force expected at each of the contact points;
adjust the properties of the downhole tool string to add a spacer at one of the contact points associated with highest contact force;
indicate location, type, or both, of the spacer; and
instruct the manufacturing system to attach the spacer to the downhole tool string based at least in part on the indicated location, type, or both, of the spacer.

2. The manufacturing system of claim 1 , wherein the design device is configured to adjust the properties of the downhole tool string by replacing a standoff attached to the downhole tool string with a roller.

3. The manufacturing system of claim 1 , wherein:
the contact parameters comprise total contact force expected along the downhole tool string, number of the contact points, where the mud cake is expected to contact the downhole tool, or any combination thereof; and
the design device is configured to:
determine a contact metric based at least in part on the contact parameters;
iteratively determine the contact parameters when the contact metric is greater than a threshold;
cease iteratively determining the contact parameters when the contact metric is no longer greater than the threshold; and
indicate the location, the type, or both, of the spacer after ceasing determination of the contact parameters.

4. The manufacturing system of claim 1 , wherein:
the properties of the downhole tool string comprise length of the downhole tool string, weight of the downhole tool string, size of a housing of the downhole tool string, material composition of the housing, type of downhole tools included in the downhole tool string, location of each spacer attached to the downhole tool string, size of each spacer attached to the downhole tool string, type of each spacer attached to the downhole tool string, or any combination thereof;
the properties of the mud cake comprise material composition of the mud cake, thickness of the mud cake, or both;
the properties of the sub-surface formation comprise material composition of the sub-surface formation, porosity of the sub-surface formation, or both; and
the properties of the borehole comprise angle of the borehole, size of borehole, or both.

5. The manufacturing system of claim 1 , wherein the model comprises a finite element analysis model configured to:
receive the properties of the downhole tool string, the properties of the borehole, the properties of the sub-surface formation, and the properties of the mud cake as inputs; and
output a curve describing the contact force expected along the downhole tool string;
wherein the design device is configured to determine whether each contact point is associated with a housing of the downhole tool string or spacers attached around the housing based at least in part on profile of the curve.

6. The manufacturing system of claim 1 , wherein the spacer comprises one of standoffs, rollers, stabilizers, or any combination thereof configured to be attached to a housing of the downhole tool string.

7. The manufacturing system of claim 1 , wherein the downhole tool string comprises:
a plurality of downhole tools configured to determine characteristics of the sub-surface formation; and
a field joint between each pair of adjacent downhole tools along the downhole tool string.

8. The manufacturing system of claim 1 , wherein:
the design device comprises a handheld computing device, a tablet computing device, a notebook computer, a desktop computer, a workstation computer, a cloud-based computing device, or any combination thereof; and
the manufacturing system comprises a manufacturing plant, a machine, equipment, or any combination thereof configured to assemble the downhole tool string.

9. A method for manufacturing a downhole tool string configured to be deployed in a borehole formed in a sub-surface formation, comprising:
determining, using a design device of a manufacturing system configured to assemble the downhole tool string, a first set of properties comprising downhole tool properties, borehole properties, formation properties, and mud cake properties;
determining, using the design device, first contact forces expected to occur between the downhole tool string and mud cake formed along a surface of the borehole based at least in part on the first set of the properties;
determining, using the design device, a second set of the properties;
determining, using the design device, second contact forces expected to occur between the downhole tool string and the mud cake;
indicating, using the design device, location, type, or both, of one or more spacers to attach to the downhole tool string based at least in part on the first contact forces and the second contact forces; and
instructing, using the design device, the manufacturing system to attach the one or more spacers to the downhole tool string based at least in part on the indicated location, type, or both, of the one or more spacers.

10. The method of claim 9 , wherein:
the first set of the properties correspond with the borehole properties, the formation properties, and the mud cake properties expected at a first location in the borehole; and
the second set of the properties correspond with the borehole properties, the formation properties, and the mud cake properties expected at a second location in the borehole.

11. The method of claim 9 , wherein:
the first set of the properties comprises at least one property of the borehole properties, the formation properties, and the mud cake properties at a first value within an uncertainty range of the property; and
the second set of the properties comprises the one property at a second value within the uncertainty range.

12. The method of claim 9 , comprising:
adjusting, using the design device, the downhole tool properties to add a first spacer to the downhole tool string based at least in part on the first contact forces;
determining, using the design device, the second set of the properties after adjusting the downhole tool properties; and
adjusting, using the design device, the downhole tool properties to add a second spacer to the downhole tool string based at least in part on the second contact forces;
wherein the one or more spacers comprise the first spacer and the second spacer.

13. The method of claim 12 , wherein:
adjusting the downhole tool properties to add the first spacer comprises adding a first standoff at a first expected contact point between a housing of the downhole tool string and the mud cake associated with highest contact force; and
adjusting the downhole tool properties to add the second spacer comprises adding a second standoff at a second expected contact point between the housing and the mud cake associated with highest contact force after the first standoff is added.

14. The method of claim 12 , wherein:
adjusting the downhole tool properties to add the first spacer comprises replacing a first standoff with a first roller, wherein the first sta

Assignees

• Schlumberger Technology Corp

Inventors

• Hsu Kai
• Song Fei
• Lan Weiming
• Copold Derek
• Landsiedel Nathan
• Battula Arvind
• Schulz Daniel
• Vasireddy Sashank

Classifications

• E21B49/088

  combined with sampling · CPC title

• E21B49/08

  Obtaining fluid samples or testing fluids, in boreholes or wells · CPC title

• E21B4/18 Primary

  Anchoring or feeding in the borehole · CPC title

• E21B49/00

  Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells · CPC title