Robust downhole pump barrel
AssigneeQ2 Artificial Lift Services LLC
InventorSanthosh Ramaswamy
Life of this patent
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Abstract
A downhole pump barrel is nickel plated to a predefined thickness followed by Boronizing a portion of nickel matrix to create Nickel Boride layer and leaving a layer of nickel between the newly formed Nickel Boride and the barrel metal surface. The top layer of Nickel Boride provides a hard surface like chrome plating which increases the wear/abrasion resistance during the sucker rod pump production. The nickel matrix disposed beneath the Nickel Boride acts as a barrier from any corrosion attacks reaching the barrel metal surface.
Claims20
A barrel for use in a sucker-rod pump assembly, comprising:
- a tubular core element defining an interior surface and a longitudinal axis;
- an interior layer formed on at least a portion of the interior surface, the interior layer including:
- a first region comprising Nickel Boride, wherein the thickness of the first region, when measured in a direction perpendicular to the longitudinal axis, is in the range of approximately 40 microns to 80 microns;
- and
- a second region substantially free of Boron, wherein the thickness of the second region, when measured in a direction perpendicular to the longitudinal axis, is in the range of approximately 1 micron to 40 microns;
- and
- wherein the second region is closer to the interior surface of the core element than the first region, when considered in a direction perpendicular to the longitudinal axis.
A method of forming a barrel for use in a sucker-rod pump assembly, the method comprising the steps of:
- electroplating a layer of nickel onto an interior surface of a tubular metal object to form a nickel-plated tubular object;
- applying a mixture containing Boron to the nickel-plated tubular object;
- heating the nickel-plated tubular object and the applied Boron containing mixture over a period of time to cause at least some of the Boron within the mixture to diffuse into the nickel layer to form a region of Nickel Boride;
- cooling the heated nickel-plated tubular object;
- and
- controlling extent and duration of the heating step to ensure that a region of the electroplated nickel layer is formed between the Nickel Boride region and the interior surface of the tubular metal object that is substantially free of Boron.
A barrel for use in a sucker-rod pump assembly, the barrel comprising a tubular member having an inner exposed surface comprising:
- an exposed surface layer formed by subjecting a base material to a diffusion process, the exposed surface layer including a diffused element and having:
- (a) a thickness of between approximately 40 and approximately 80 microns, (b) a first relative hardness, and (c) a first relative resistance to corrosion;
- an intermediate layer comprising the base material, the intermediate layering being substantially free of the diffused element and having:
- (a) a thickness of between approximately 1 and approximately 40 microns;
- (b) a second relative hardness, and (c) a second relative resistance to corrosion;
- and
- a core layer to which the intermediate layer was applied.
Dependencies are inferred from the claim text.