Mud pump systems for wellbore operations

Abstract

A system for pumping a drilling fluid mixture, the system, in certain aspects, having a pump apparatus, the pumping apparatus having a body with an inlet and an outlet, a suction valve and a discharge valve in the body for selectively controlling flow through the body, or each valve having a curved valve seat and a valve member with a curved seating surface, the valve member selectively movable to seat against the curved valve seat to prevent the flow of the drilling fluid mixture past the valve seat; and, in one aspect, a seal in the curved valve seat against which the valve member is also sealable. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b).

Description

BACKGROUND OF THE INVENTION[0001]1. Field Of The Invention[0002]This present invention is directed to drilling wellbores in the earth, to systems for pumping drilling fluid (“mud”) for such operations, to mud pumping systems and valves for them, and methods of their use.[0003]2. Description of Related Art[0004]The prior art discloses a wide variety of drilling systems, apparatuses, and methods including, but not limited to, the disclosures in U.S. Pat. Nos. 6,944,547; 6,918,453; 6,802,378; 6,050,348; 5,465,799; 4,995,465; 4,854,397; and 3,658,138, all incorporated fully herein for all purposes. The prior art discloses a wide variety of drilling fluid pumps (“mud pumps”) used in drilling operations and pump systems, for example, and not by way of limitation, those pumps and systems disclosed in U.S. Pat. Nos. 6,257,354; 4,295,366; 4,527,959; 5,616,009; 4,242,057; 4,676,724; 5,823,093; 5,960,700; 5,059,101; 5,253,987; in U.S. applications Ser. No. 10 / 833,921 filed Apr. 28, 2004 (all s...

AI Technical Summary

Benefits of technology

[0013]In certain particular aspects of a mud pump system according to the present invention, a mud pump valve has a tapered spring biased against a valve member which enhances the free seating movement of a valve member.

[0019]Such valves with a tapered spring for facilitating effective seating of the valve member against the valve seat; and

Problems solved by technology

Both valves, the suction valve and the discharge valve, are subjected to the erosive and damaging effects of the flow of drilling fluid.

Also, mud pumps which can pump relatively hot drilling fluid at, e.g., 500 to 2000 gallons per minute, force the erosive drilling fluid against the valve parts at high velocities which add to the fluid's damaging effects.

If either surface is not flat, or if one surface does not contact the other in a substantially parallel (flat surface to flat surface) manner, ineffective or inefficient valve operation may result.

The erosive and / or damaging effects of drilling fluid flow through a valve can damage the seating surfaces so that the ideal flat-surface-to-flat surface seating is not achieved.

Also, the drilling fluid can damage a guide (e.g. ribs and a channel for receiving a stem or rod projecting from a valve member) or guide fingers so that the ideal surface seating is not achieved.

In some instances, damage to a guide or to guide fingers results in a flat valve member surface contacting a flat seating surface at an angle so that effective valve closure is not possible or so that the valve is insufficiently closed for efficient operation.

In some aspects, erosive drilling fluid flow renders initially-flat seating surfaces non-flat with resulting ineffective sealing and valve closure.

The movement of the valve member is not controlled, i.e., it is subject to a surge of fluid under pressure.

This surge of fluid can have deleterious effects on valve parts.

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