SOLIDS REMOVAL HEADER

Abstract

A solids removal header comprises a substantially hollow tubular member having an interior, a first section having a first interior, and a second section having a second interior. The first section is fluidly connected to the second section. The solids removal header further comprises an inlet, an outlet, and a connection loop. The connection loop has an interior to fluidly connect the first interior and second interior, and to define a primary fluid path for any wellbore fluids to travel through when moving between the inlet and outlet during solid separation operations. At least one fluid connecting member is provided to create at least one additional fluid path between the first interior and the second interior.

Description

FIELD OF THE INVENTION

This invention relates generally to sand filters. More particularly, the invention relates to a pipeline header to remove sand and other particulates from a fluid stream from a well.

BACKGROUND OF THE INVENTION

The background information discussed below is presented to better illustrate the novelty and usefulness of the present invention. This background information is not admitted prior art.

Oil, gas and other hydrocarbon wells are often optimized using a process called hydraulic fracturing. This fracturing, or “fracking,” process begins with the drilling of a well into a rock formation. Then a hydraulic fluid, typically a mixture of water, sand and a small amount of other additives (blend of chemicals), is injected into the well under pressure. Other solid materials, such as treated sand or man-made ceramic materials may also be added (or used instead of sand). These solid materials in the hydraulic fluid are referred to as propping agents or proppants. The pressurized hydraulic fluid, along with the proppants, creates hairline cracks in the rock formation. These cracks, held open by the proppants, allow the oil, gas and other hydrocarbons to escape the rock formation and flow up through the wellbore to the surface.

However, after fracking, the well will often produce a fluid stream heavily contaminated with the proppants and rock formation particles. As such, the well's fluid stream is then typically composed of one or more of: oil, natural gas, water, fracking slurry, rock dust and rock debris, sand and/or other proppants. It is known that these solid particles in the well's fluid stream, which collectively may be referred to as particulates or solids, pose a problem for the well's operator. Overall, natural or manmade particulates can cause a multitude of producing problems. For example, in flowing wells abrasive particulates can “wash through” metals in piping damaging equipment and creating leaks and potentially hazardous conditions. The particulates can also fill-up and stop-up surface flow lines, vessels, and tanks.

It is therefore desirable to remove or separate these particulates from the well's fluid stream. For example, a large vertical sand separator is commonly provided at the surface of the well to remove the proppants that may be present as a result of fracking. Conventional sand separation systems often rely on gravity to separate the proppants from the fluids that are produced from a well. However, there are various problems with the use of conventional sand separators. The large size of this type of apparatus makes it difficult to transport and install. Additionally, because of material cost, the sheer size of apparatus makes it more expensive.

Therefore, what is needed is solids removal or separator apparatus that does not suffer from the disadvantages of the present apparatus and systems.

SUMMARY OF THE INVENTION

In an embodiment of the invention, there is provided a solids removal header to contain wellbore fluids under pressure and to separate solids therefrom. The solids removal header comprises a substantially hollow tubular member having an interior and defining a volume, a first section have a first longitudinal axis and a first interior, and a second section having a second longitudinal axis and an second interior. The first section is fluidly connected to the second section so that their respective interiors are in fluid communication with each other and define at least part of the volume. The solids removal header further comprises an inlet, an outlet, and a connection loop. The connection loop has an interior to fluidly connect the first interior and second interior, and to define a primary fluid path for any wellbore fluids to travel through when moving between the inlet and outlet during solid separation operations. At least one fluid connecting member is provided to which creates at least one additional fluid path between the first interior and the second interior.

In another embodiment of the invention, a plurality of fluid connecting members, and associated plurality of additional fluid paths), are provided at periodic intervals along the first and second sections.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:

FIG. 1 is a sectioned side view of one embodiment of the solids removal header of the present invention;

FIG. 2 is close up view of area 2 in FIG. 1, taken along line A-A;

FIG. 3 is a front elevation view of the embodiment of FIG. 1, taken along line A-A;

FIG. 4 is a close up, interior perspective view of one standpipe and downcomer configuration for the embodiment of FIG. 1;

FIG. 5 is perspective view of a scraper for use with the embodiment of FIG. 1;

FIG. 6 is a sectioned side view of the embodiment of the solids removal header of FIG. 1, indicating flow paths; and

FIG. 7 is a perspective view of another embodiment of the solids removal header of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is of preferred embodiments by way of example only and without limitation to the combination of features necessary for carrying the invention into effect. Reference is to be had to the Figures in which identical reference numbers identify similar components. The drawing figures are not necessarily to scale and certain features are shown in schematic or diagrammatic form in the interest of clarity and conciseness.

The present invention provides an apparatus, system and method for separating sand, proppants and other solids from wellbore fluids F (such as oil, gas and other liquids) that may be produced from a well.

A first embodiment of the solids removal header 10 of the present invention is shown in FIGS. 1-6. A second embodiment of the solids removal header 10 is shown in FIG. 7. In these embodiments, the solids removal header 10 is a substantially hollow tubular member having an interior 10i defining a volume 10v. The solids removal header is suitable to contain wellbore fluids F under pressure. Solids removal header 10 is preferably characterized as an elongated, tubular pressure vessel comprised of a first section 12 and a second section 14.

The first and second sections 12, 14 are substantially hollow tubular members, each defining their own respective longitudinal axis 12l, 14l (e.g. see FIG. 7).

Preferably the first and second sections 12, 14 are mounted on a support structure 20 so that the first section 12 is positioned substantially above the second section 14, and so that their respective longitudinal axes 12l, 14l are substantially parallel to each other along a vertical plane. Support structure 20 may mount the solids removal header 10 above the ground G or other suitable surface (such as a concrete pad). In this preferred orientation, the first section 12 may then also be referred to as the upper section, while the second section 14 may then also be referred to as the lower section. Similarly, when in this preferred orientation, the first section 12 will have a top 12t and a bottom 12b, and the second section will also have a top 14t and a bottom 14b, with the bottom 12b of the first section 12 then substantially facing the top 14t of the second section 14.

Preferably, the solids removal header 10 is a pressure vessel suitable for pressures up to at least 3000 psi and is generally constructed of steel, carbon steel or other appropriate materials to maintain such pressure. For example, first and second sections 12,14 may be constructed from grade 359, category II, schedule 120, 16 inch outside diameter pipe. Alternatively, first and second sections 12,14 may be constructed from grade 359, category II, schedule 80, 14 inch outside diameter pipe. Preferably, the solids removal header 10 is also provided with the appropriate conventional seals, o-rings, fittings, flanges, flange blinds and other conventional components to maintain pressure within the interior 10i during solids separation operations.

The first section 12 may be mounted above the second section 14 at a variety of heights H. For example, if the outside diameter of the first and second sections 12,14 is 16 inches, then preferably the height H (or distance between) the first and second sections 12, 14 is one foot. The first and second sections 12, 14 also each comprise a first end 12a, 14a (at one end of the longitudinal axis 12l, 14l) and a second end 12b, 14b (at the opposing, second end of the longitudinal axis 12l, 14l); see FIG. 7. The two sections 12, 14 are fluidly connected to each other so as to have their respective interiors 12i, 14i be in fluid communication with each other and thereby defining a substantial part of the volume 10v. This may be accomplished by means of a tubular connection loop 16 that connects the second end 12b of the first section 12 to the second end 14b of the second section 14. Like the first and second sections 12,14, the connection loop 16 has an interior 16i to accept wellbore fluids F. The connection loop 16 may be a simple hollow, looped tubular member (e.g. as shown in FIG. 7) or it may further comprise one or more flanged connections 16f (e.g. FIG. 1). Flanged connections 16f may be sealed with a blind flange (not shown) and conventional sealing member (not shown) during solid separation operations. Flanged connections 16f may be opened so as to provide additional clean-out and inspection access points during clean out operations.

The solids removal header 10 further comprises an inlet 30 and an outlet 32. Preferably, the inlet 30 is provided at the first end 12a of the first section, the connection loop 16 is provided to fluidly connect the second end 12b of the first section to the second end 14b of the second section 14, and the outlet is provide at the first end 14a of the second section 14. As will now be clear to those skilled in the art, the first and second sections 12,14, along with the connection loop 16, define a substantial part of the interior volume 10v whereby their interiors 12i, 14i, 16i provide a continuous primary fluid path P for any wellbore fluids F to travel between the inlet 30 and outlet 32 during solid separation operations (see FIG. 6).

Preferably the inlet 30 is a flanged connection point 30f (e.g. FIG. 1) to allow easy pipe connection to the wellhead W. More preferably the outlet 32 further comprises a 45 degree elbow 32e (see FIG. 1). As noted above, preferably, inlet 30 and outlet 32 are spaced from each other so as to be at substantially opposite ends of the primary fluid path P.

In addition to the connection loop 16, the solids removal header 10 further comprises at least one fluid connecting member 40 which provides fluid communication and an additional fluid path P′ between the first section's interior 12i and the second section's interior 14i. Preferably, a plurality of such fluid connecting members 40 are provided at periodic intervals along the first and second section's longitudinal axes 12l, 14l, providing for a plurality of additional, or secondary fluid paths P′ (see FIG. 6). More preferably, fluid connecting members 40 each are a hollow tubular member which are positioned between the bottom 12b of the first section 12 and the top 14t of the second section. Even more preferably, the interior cross sectional area of a fluid connecting member 40 (or the total interior cross sectional area of a plurality of fluid connecting members 40) is smaller than the interior cross sectional area of the connection loop 16, so that the wellbore fluid F (traveling from inlet 30 to outlet 32) will primarily flow through connection loop 16 along the primary fluid path P, but wherein at least some of the wellbore fluid F (traveling from inlet 30 to outlet 32) will flow along the one or more secondary fluid paths P′ during solid separation operations.

The addition of the at least one fluid connecting member 40, and the creation of at least one secondary fluid paths P′ during solid separation operations, will result in turbulence and eddies within the interior volume 10v. This turbulence and eddies will then result in the separation of solids S (such as sand or other proppants) from the liquid and gas portions of the wellbore fluid F as it travels from the inlet 30 to the outlet 32. Advantageously, because fluid connecting member 40 connects the interior volumes 12v, 14v from the bottom 12b of the first section 12 to the top 14t of the second section, solids S that separate from the wellbore fluid F will be drawn by gravity through the fluid connecting member 40 and be deposited on the bottom 14b of the second section.

Preferably, each fluid connecting member 40 further comprises an upper section or standpipe 42 that projects upwards into the first section 12 (from the bottom 12b) and a lower section or downcomer 44 that projects downward into the second section 14 (from the top 14t); see FIGS. 1 and 4. Advantageously, each of the standpipe 42 and downcomer 44 will create a barrier and tortuous path (within the interior 10i) for the wellbore fluid F as it moves between inlet 30 and outlet 32 during solid separating operations. Such barrier and tortuous path will further facilitate the separation of solids S from the gaseous and liquid components of the wellbore fluid F. More advantageously, because standpipe 42 and downcomer 44 are substantially integral with the fluid connecting member 40, solids S are directed down through the interior 40i of said member 40 so as to accumulate on the second sections bottom 14b substantially thereunder.

Preferably, downcomer 44 is a substantially tubular member which projects down into the second section 14 past the center line of said section 14 (as taken along the longitudinal axis 14l), so as to create as large a barrier as possible. More preferably, standpipe 42 projects into the first section 12 past the center line of said section 12 (as taken along the longitudinal axis 12l), so as to create as large a barrier as possible. Even more preferably, standpipe 42 provide a concave curvature 42c wherein the concave aspect 42c directs any wellbore fluid that travels through the member 40 along the secondary fluid paths P′ into said members' interior 40i. Still even more preferably, in embodiments where in a plurality of fluid connecting members 40 are provided, the concave aspects 42c are oriented in a substantially alternating arrangement so that paired member 40 have their concave curvatures 42c substantially face each other.

Preferably, outlet 32 (and any elbow 32e component) are provided substantially on the second section's top 14t near the first end 14a. Advantageously, when solids S are deposited on the bottom 14b of the second section 14b, such solids S will remain within the solids removal header 10; while any remaining gaseous and liquid portions of the wellbore fluid F will exit out the outlet 32 substantially free of any solids S. More preferably, the solids removal header 10 further comprises one or more drain outlets 50 (to drain the bottom 14b of the second section 14) and one or more wash inlets 52 (to provide wash out fluid into the top 12t of the first section 12). Drain outlets 50 and wash inlets 52 may be conventional flanged connections that are sealed (e.g. with a blind flange and gasket) during solid separation operations, but which are opened during clean out operations. Drain outlets 50 may be connected in a conventional manner to a vacuum truck during clean out operations, whereby the vacuum truck will suck out any accumulated solids S from the interior volume 10v. Wash inlets 52 may be connected to a source of wash-out fluid during clean out operations, whereby the wash-out fluid will move from the first section 12 to the second section 14 and carry any accumulated solids S out to the drain outlets 50. Advantageously, since the first section 12 is preferably positioned above the second section, gravity will assist to move such wash-out fluid and any accumulated solids S out through the drain outlets 50.

Preferably, a wash inlet 52 is provided for each fluid connecting member 40 and is positioned substantially above such fluid connecting member 40 (see FIG. 1). Advantageously, any wash-out fluid will quickly and efficiently wash out any solids S that may have accumulated on the bottom 14b of the second section 14 underneath such fluid connecting member 40. More advantageously, wash inlet 52 can also be opened (e.g. during clean out operations) to obtain easy physical access to the interior of the fluid connecting member 40, so as to allow an operation to clear any plugs or obstructions that may be present within such fluid connecting member 40.

Preferably, a sealed access door 60 is provided at the first end 14a of the second section 14, so as to allow an operator to obtain physical access to that section's interior 14i during clean out operations. The access door 60 may be a Yale™ type quick opening closure. Even more preferably, the cross sectional area of the first end 14a of the second section 14 is reduced in an eccentric manner between outlet 32 and any such access door 60, so as to provide neck region 14n having a slope that is oriented downward from top 14t to bottom 14b (see FIG. 1). Advantageously, as wellbore fluids F are forced to navigate around any elbow 32e and out the outlet 32, any remaining solids S not yet separated out will then separate and collect in said neck region 14n. More advantageously, access door 60 can be opened during clean out operations, to quickly and easily remove such solids S that may have accumulated in the neck region 14n.

Preferably, a scraper 70 is provided to assist with any cleanout of accumulated solids S from the bottom 14b of the second section 14. Scraper 70 is preferably a longitudinal member, having a longitudinal axis 701, along which a plurality of scraper plates 72 are provided and oriented with their planes in a substantially perpendicular manner to said longitudinal axis 701 (see FIG. 5). Scraper 70 preferably further comprises a handle 70h. Scraper 70 is preferably of such dimensions so as to fit through door 60 and be housed within the second section's interior 14i, preferably resting on the bottom 14b. More preferably, scraper 70 has a longitudinal length so as to substantially extend between first and second ends 14a, 14b (see FIG. 1). Even more preferably, scraper 70 has a height that is lower than any downcomers 44 that may project into the interior 14i. Advantageously, solids S may accumulate on the bottom 14b, between the plurality of scraper plates 72 and, during clean out operations, scraper 70 may be pulled out of the interior 14i (through door 60), thereby scraping and removing said accumulated solids S out through door 60 therealong with. As will now be apparent, scraper 70 will significantly increase the efficiency of solid S clean out operations.

Preferably, one or more lifting points or lifting lugs 80 are provide on header 10, to allow for easy moving and manipulating of the header 10.

Those of ordinary skill in the art will appreciate that various modifications to the invention as described herein will be possible without falling outside the scope of the invention. In the claims, the word “comprising” is used in its inclusive sense and does not exclude other elements being present. The indefinite article “a” before a claim feature does not exclude more than one of the features being present.

Claims

1. A solids removal header to contain wellbore fluids under pressure and to separate solids therefrom, the solids removal header comprising:

a substantially hollow tubular member having an interior (10i) defining a volume (10v);

a first section (12) have a first longitudinal axis (12l) and an first interior (12i);

a second section (14) having a second longitudinal axis (14l) and an second interior (14i);

wherein the first section (12) is fluidly connected to the second section (14) so that their respective interiors (12i, 14i) are in fluid communication with each other to define at least part of the volume (10v);

the solids removal header further comprising:

an inlet (30);

an outlet (32);

a connection loop (16) having an interior (16i) to fluidly connect the first interior (12i) and second interior (14i) to define a primary fluid path (P) for any wellbore fluids (F) to travel between the inlet (30) and outlet (32) during solid separation operations;

at least one fluid connecting member (40) to provide at least one additional fluid path (P′) between the first interior (12i) and the second interior (14i).

2. The solids removal header of claim 1 further comprising a support structure (20); and

wherein the first and second sections (12,14) are mounted on the support structure (20) so that the first section (12) is positioned substantially above the second section (14), and so that the first and second longitudinal axes (12l, 14l) are substantially parallel to each other along a vertical plane.

3. The solids removal header of claim 1 wherein a plurality of fluid connecting members (40), and associated plurality of additional fluid paths (P′), are provided at periodic intervals along the first and second longitudinal axes (12l, 14l).

4. The solids removal header of claim 1 wherein the total interior cross sectional area of the at least one fluid connecting member (40) is smaller than the cross sectional area of the connection loop's interior (16i).

5. The solids removal header of claim 1 wherein the first section (12) has a bottom (12b) and a top (12t);

wherein the second section (14) has a bottom (14b) and a top (14t);

wherein the at least one fluid connecting member (40) and the least one additional fluid path (P′) are positioned between the first section's bottom (12b) and the second section's top (14t); and

wherein at least some solids (S) that separate from the wellbore fluids (F) will be drawn by gravity through the at least one fluid connecting member (40) and be deposited on the bottom (14b) of the second section (14).

6. The solids removal header of claim 5 wherein the at least one fluid connecting member (40) further comprises a standpipe (42) which projects into the first interior (12i) and a downcomer (44) which projects into the second interior (14i)

7. The solids removal header of claim 6 wherein the standpipe (42) further comprises a concave curvature (42c).

8. The solids removal header of claim 1 further comprising at least one drain outlet (50) and at least one wash inlet (52).

9. The solids removal header of claim 5 wherein the second section (14) further comprises a first end (14a) and a sealed access door (60) is provided at said first end (14a).

10. The solids removal header of claim 9 further comprising a scraper (70) to assist with any cleanout of accumulated solids (s) form the bottom (14b) of the second section (14).