BACKGROUND INFORMATION

Technical Field

The present disclosure relates to apparatus, systems, and methods useful for testing the quality of tubular goods (hollow or solid), particularly automated inspection of tubular goods (sometimes referred to in the oil & gas industry as “oil country tubular goods”, and herein sometimes as simply “OCTG”).

Background Art

As noted in assignee's previous U.S. Pat. Nos. 7,397,238 and 7,622,917, electromagnetic inspection (EMI) of metal pipe or solid metal tubular members by magnetic means conventionally involves magnetizing the member to create a magnetic field which extends circumferentially and is characterized by lines of magnetic flux which extend either axially of the tubular member or generally perpendicular to its axis, dependent on the manner by which magnetism is induced. In many of the present systems, current flow through a wire coil positioned about the tubular member forms magnetic lines of flux through the opening of the coil which extend axially of the member under inspection. In other systems, current flows axially of the tubular member within the wall thereof so as to create a magnetic field, the lines of flux of which extend circumferentially about the tubular member in an orientation substantially perpendicular to the tubular member. The presence of structural flaws or anomalies in the wall of the tubular member, such as surface nicks or pits, cracks, voids, or various crystalline discontinuities, disturbs the uniformity of a magnetic field in the wall of the tubular member. Accordingly, the structural integrity of the tubular member and its relative freedom of such flaws may be inspected by sensing and detecting the magnetic field variations with sensors disposed closely adjacent the surface of the tubular member.

The sensing of variations in a magnetic field in a pipe wall is customarily achieved by passing or moving an induction coil or similar device through the magnetic field and any magnetic field variations to induce voltages in the coil indicative of the magnetic field variations. The voltages or voltage signals may then be transmitted to appropriate recording and processing equipment. For optimum detection sensitivity and for detection of very small cracks in a pipe wall which can be a few thousandths of an inch in depth, and as explained in U.S. Pat. No. 4,916,394, it is necessary that the detecting or sensor coil be placed closely adjacent the exterior surface of the tubular member. Normally the adjacent coil is disposed from 0.002 inches (0.051 mm) to 0.020 inches (0.51 mm) relative to the surface of the tubular member with an axis of the coil substantially perpendicular to the surface. In the sensor shoes described in the '394 patent, one or more sensor coils are mounted in a recess in a non-magnetic support, such as brass, using a potting material such as epoxy. The brass support is provided with a thin magnetically transparent shim (such as stainless steel) covering the sensor coils, and a pair of wear-resistant contact members are attached to the shim, made for example of tungsten carbide or beryllium-copper alloy, adapted to contact with the surface of the tubular member in a manner so that the sensing coils are supported closely adjacent the surface of the tubular member at an optimum distance or spacing. The coils are protected from direct contact with the surface of the pipe by means of the thin shim of stainless steel. It is also known to use hard, non-flexible plastic shoe supports.

Inspecting the surface of the tubular members requires that the inspection sensor be moved along the surface in a predetermined inspection path. In one widely used pipe inspection apparatus, a plurality of sensor shoes are applied to the surface of the pipe in circumferential spacing thereabout and each of the sensor shoes is moved relatively to the pipe in a circumferential helical path whereby the plurality of sensors provides more than 100 percent coverage of the pipe surface. The relative movement may be affected by moving the sensors longitudinally while rotating the sensor shoes around a stationary pipe or the pipe can be moved longitudinally while the sensors are rotated about the pipe. In any event, there is relative sliding movement between the sensor shoes and the pipe surface, which causes wear of the contact surfaces of a sensor shoe by extensive use. The shim also can come into contact with the pipe and can be similarly eroded. The wearing down of the contact surfaces and shim results in the coils being supported from the pipe surface inside the optimum spacing range or possibly being damaged by eventual contact with the pipe. When either event occurs, either a new sensor shoe is required, or adjustments to the contact surfaces and/or shim as explained in the '394 patent must be made.

Furthermore, sensor shoes are customarily designed for use with a specific diameter of pipe, and the contact surfaces of a sensor shoe are fixed in a permanent orientation such that when placed in contact with the surface of the pipe, the sensing coil is positioned for optimum detection sensitivity. Accordingly, a given sensor shoe is designed for inspection of only one diameter of pipe and is inappropriate for use as an inspection sensor for pipes of a different diameter since for such pipe diameters the sensing coil is supported at other than an optimum distance from the surface to be inspected. The '394 patent addresses this problem using a pair of adjustable, wear-resistant elongate contact members having triangular cross-section, whereby adjustment screws in slots are employed for adjustment of each; however, the adjustment of these contact members may be physically challenging, and the adjustment (alignment) must be identical for both. U.S. Pat. No. 4,602,212 describes sensors holders (housing therein magnetic field detectors) that are mounted radially movably through a link mechanism providing a leaf spring to push the sensor holders radially inwardly. However, these leaf springs simply provide an action urging the entire sensor structure against the member being inspected; there is no provision for accommodating inspection of out-of-round tubulars with the same arrangement of sensors. U.S. Pat. No. 8,020,460 describes a similar arrangement, whereby a flexible sensor mount may comprise an elastic material, such as a polyurethane elastomer, thereby permitting relative motion of a relatively rigid sensor housing that houses one or more sensors. Non-flexible, rigid, sensor shoes are less sensitive to out-of-round tubulars, or tubulars having shallow external concave deformities. If there is a defect in the tubular, such as a crack, under or within the concavity, sensors within these non-flexible, rigid shoes may miss the defect entirely, producing “cut-outs” in the electronic inspection signals received from such sensors. U.S. Pat. No. 7,640,811 describes a mechanical probe extension coupler that presses an acoustic inspection probe (described in U.S. Pat. No. 7,337,673) against the structure to adjust for surface contour changes. By sensing pressure increase or decrease outside of a preferred range due to the contour changes, the probe extension adjusts the pressure exerted on the probe, maintaining a consistent standoff distance for one or more acoustic transducers. However, if the surface contour change is a concavity smaller than the probe sleds, this technique will not succeed in finding a defect in the tubular, such as a crack, under or within the concavity.

One goal of OCTG producers is high tonnage production per day or other time period, and any process or sub-process that slows down the manufacturing of OCTG or other tubulars is disadvantageous economically. In short, the more tons of pipe out the door the better. From the above it is evident that there is a need in the art for improvements in tubular member inspection methods and apparatus, particularly for those that can inspect out-of-round tubulars or tubulars having shallow external concave deformities, without great loss of time in changing or adjusting the sensors shoes to accommodate these tubulars, and with less signal cut-outs. The apparatus, systems, and methods of the present disclosure are directed to these needs.

SUMMARY

In accordance with the present disclosure, apparatus and systems for inspecting OCTG and other tubulars are presented, and methods of using same to inspect OCTG and other tubulars are described which reduce or overcome many of the faults of previously known apparatus, systems, and methods.

A first aspect of the disclosure is an EMI inspection shoe (30) comprising:(a) a flexible, generally arcuate body (40) comprising a flexible material, the flexible, generally arcuate body (40) having a leading end (42), a trailing end (44), a non-working major face (46), and a working major face (48), the leading end (42), trailing end (44), non-working major face (46), and working major face (48) at least partially defining an inspection zone (50) therebetween;(b) one or more magnetic flux detectors (80) carried by the flexible, generally arcuate body (40) in the inspection zone (50); and(c) one or more pressure actuators (52) removably attached to the non-working face (46) and configured to exert pressure on one or more regions (90) of the non-working major face (46) of the flexible, generally arcuate body (40) in the inspection zone (50) during an EMI inspection of a tubular (2), forcing the flexible, generally arcuate body (40) to contort into a generally contoured shape as it passes over a contoured region (20) of the tubular (2).

In certain embodiments the flexible material may have a 300% modulus less than or equal to about 2100 psi (about 14 MPa), or ranging from about 2000 psi (about 14 MPa) to about 1000 psi (about 7 MPa), when tested in accordance with ASTM D412-2015 (Method A); or a 100% modulus less than or equal to about 1000 psi (about 7 MPa), or ranging from about 25 psi (about 0.2 MPa) to about 1000 psi (about 7 MPa), when tested in accordance with ASTM D412-2015 (Method A); or a compression set (CB or CB) less than or equal to about 50, or less than or equal to about 25, less than or equal to about 10, or less than or equal to about 5, or about 1, or about 0, when tested in accordance with ASTM D395-2018 (Method B). In certain embodiments the flexible material may have a 300% modulus less than or equal to about 2100 psi (about 14 MPa), or ranging from about 2000 psi (about 14 MPa) to about 1000 psi (about 7 MPa); and a 100% modulus less than or equal to about 1000 psi (about 7 MPa), or ranging from about 25 psi (about 0.2 MPa) to about 1000 psi (about 7 MPa); and a compression set (CB or CB) less than or equal to about 50, or less than or equal to about 25, less than or equal to about 10, or less than or equal to about 5, or about 1, or about 0. In certain embodiments the flexible material may have an abrasion resistance ranging from about 0 to about 200 mm3, or from about 20 to about 150 mm3, or from about 60 to about 135 mm3, when tested in accordance with ASTM D5963-04(2015).

In certain embodiments the one or more pressure actuators (52) may comprise one or more springs, in certain embodiments having a spring force able to force the flexible material into a concave contour, where the concave contour has a maximum depth of about 0.1 inch (about 2.5 mm), or about 0.2 inch (about 5 mm), or about 0.3 inch (about 7.5 mm), or about 0.4 inch (about 10 mm), or about 0.5 inch (12.5 mm). In certain embodiments the one or more pressure actuators (52) may comprise a differential pressure actuator. In certain embodiments the differential pressure actuator may comprise a closed conduit arranged in a curvilinear structure.

In certain embodiments the EMI inspection shoes may further comprising one or more pressure plates (70) interposed between the one or more pressure actuators and the non-working face of the flexible, generally arcuate body (40). In certain embodiments the one or more pressure plates (70) may have a flexural strength greater than the flexible material of the flexible, generally arcuate body (40); in certain embodiments the flexural strength may be about 40 MPa or higher, or from about 40 MPa to about 270 MPa, or from about 70 MPa to about 200 MPa (when tested in accordance with ASTM D-790-2017).

A second aspect of the disclosure is a tubular member EMI inspection apparatus comprising:(a) a frame (102);(b) at least one magnetic flux generator (104) contained in a coil annulus (108) and a detector assembly (106) supported by the coil annulus (108);(c) the coil annulus (108) and the detector assembly (106) each having inlet and outlet openings (110,112) for passing a tubular member (2) there through, the detector assembly (106) having one or more magnetic detectors (116) (magnetic, eddy current, or both) configured to be spaced a first distance from the tubular member (2) during an inspection; and(d) the one or more magnetic detectors (116) each contained in one or more EMI detector shoes (30), the one or more EMI detector shoes (30) comprising:(i) a flexible, generally arcuate body (40) comprising a flexible material, the flexible, generally arcuate body (40) having a leading end (42), a trailing end (44), a non-working major face (46), and a working major face (48), the leading end (42), trailing end (44), non-working major face (46), and working major face (48) at least partially defining an inspection zone (50) therebetween;(ii) one or more magnetic flux detectors (80) carried by the flexible, generally arcuate body (40) in the inspection zone (50); and(iii) one or more pressure actuators (52) removably attached to the non-working face (46) and configured to exert pressure on one or more regions (90) of the non-working major face (46) of the flexible, generally arcuate body (40) in the inspection zone (50) during an EMI inspection of a tubular (2), forcing the flexible, generally arcuate body (40) to contort into a generally contoured shape as it passes over a contoured region (20) of the tubular (2).

In certain embodiments the frame (102) may comprise a steel welded sub-frame supporting one or more pinch roller systems (130), the coil annulus (108) may comprise rigid aluminum, and the apparatus may be configured to perform a quality EMI inspection of OCTG pipe with wall thicknesses up to about 0.625 inch (about 15.9 millimeters), and with production speeds up to about 150 feet per minute (about 46 meters per minute). In certain embodiments the EMI inspection apparatus may be configured to operate continuously. In certain embodiments the EMI inspection apparatus may be configured to inspect plain-end OCTG materials having an outer diameter ranging from about 2⅜ inches (about 60.3 mm) to about 8.00 inches (about 203.2 mm), or ranging from about 4½ inches (114.3 mm) to about 14.00 inches (355.6 mm). In certain embodiments the EMI inspection apparatus may be configured to perform EMI inspection methods including magnetic flux leakage technology for OD and ID longitudinal and transverse flaws, magnetic flux density for 100% coverage of the wall thickness variations, and an eddy current system for comparison of metallurgical mass and permeability differences.

Another aspect of the disclosure is a method of EMI inspecting tubular members comprising passing a tubular member through an apparatus of the present disclosure or driving an apparatus of the present disclosure past the tubular member and detecting variations in the magnetic field produced by defects in the tubular member. In certain embodiments the variations in the magnetic field may be detected by the magnetic detectors spaced so that their respective magnetic fields abut and provide a minimum of 100 percent inspection of the tubular member.

In certain embodiments the tubular member, OCTG or other tubular, may be hollow; in other embodiments the tubular member may be solid. In certain embodiments the EMI inspection apparatus frame may comprises a steel welded sub-frame supporting one or more pinch roller systems, and the coil annulus may comprise rigid aluminum.

In certain embodiments the EMI inspection shoes may be configured to provide a set off distance for the magnetic detectors of at least 0.030 inch (about 0.08 mm); in certain other embodiments the set off distance may range from about 0.050 inch (about 1.27 mm) up to about 0.5 inch (about 12.7 mm). In certain embodiments the detector assembly may comprises a plurality of detector support sub-assemblies. Certain embodiments may comprise one or more actuators selected from the group consisting of pneumatic, hydraulic, and electronic actuators, and combination thereof, for example, to actuate the one or more pressure actuators, and in certain embodiments, telescoping members, to actuate an iris, and the like.

In certain embodiments various components (for example, but not limited to the magnetic flux generator, detectors, telescoping supports, and/or iris (as disclosed in assignee's co-pending U.S. patent application Ser. No. 16/987,211, filed Aug. 6, 2020) may be operated remotely via wired or wireless communication, and/or locally via on-board batteries, an on-board motor, and one or more programmable logic controllers (PLCs). Certain embodiments may comprise a software module including one or more algorithms for calculating or presenting parameters selected from the group consisting of longest substantially longitudinal flaw, deepest substantially longitudinal flaw, longest substantially transverse flaw, deepest substantially transverse flaw, minimum and maximum wall thickness, and combinations thereof. In certain embodiments the detector assembly may comprise one or more electromagnetic acoustic transducer (EMAT) sensors.

Certain embodiments may further comprise a tubular conveyor sub-system on which the tubulars traverse before and after being inspected. Certain embodiments may further comprise one or more actuators (in certain embodiments, one or more robots) adapted to pick up the tubular being inspected and insert the tubular into an EMI inspection apparatus as disclosed in accordance with the present disclosure, the one or more actuators selected from the group consisting of pneumatic, hydraulic, and electronic actuators, and combination thereof.

These and other features of the apparatus, systems, and methods of the disclosure will become more apparent upon review of the brief description of the drawings, the detailed description, and the claims that follow. It should be understood that wherever the term “comprising” is used herein, other embodiments where the term “comprising” is substituted with “consisting essentially of” are explicitly disclosed herein. It should be further understood that wherever the term “comprising” is used herein, other embodiments where the term “comprising” is substituted with “consisting of” are explicitly disclosed herein. Moreover, the use of negative limitations is specifically contemplated; for example, certain apparatus, systems, and methods in accordance with the present disclosure may comprise a number of physical or chemical components and features but may be devoid of certain optional physical, chemical or other components and features.

