Collet Connector Comparison

Transcription

1 Collet Connector Comparison

2 Collet Connector Comparison As drilling depths have increased over the years, Cameron collet connectors have evolved to address issues concerning higher internal and external pressures, ever-increasing applied bending and tension loads, and extreme operating conditions. Additionally, Cameron collet connectors are designed to fulfill a variety of requirements caused by restricted space, high preload and fatigue life, as well as customer requirements for unique operating environments. Cameron Model 70, HC, HCH4 and DWHC Collet Connectors are typically used for connection of the BOP stack to the wellhead, and to secure the lower riser assembly to the top of the BOP. While these collet connectors utilize the same basic design, their preload and structural load capabilities vary. All Cameron collet connectors have the following features: High strength and stiffness with a direct load path through the connector. Metal-to-metal sealing AX gaskets on the collet end ensure seal integrity. A new version of the AX gasket with a contingency seal may be used with the DWHC. Positively driven-open collet segments during unlock ensure that no overpull is required to disconnect. A secondary unlock function is also included in the design. Inconel inlays on all sealing surfaces exposed to seawater. Available with studded, flanged or clamped tops. Available with secondary unlock pistons. Inherent self-locking characteristics. Model 70 Collet Connector The Model 70 Collet Connector forms a tight seal while withstanding the bending stresses and separating forces caused by well pressure, riser tension and vessel motion. Features include: Cylinders may be easily repaired or replaced. Short swallow up, tapered hub profile and positive unlocking system allow disconnection at angles up to angles on the clamp segment faces and a large actuating piston area create a greater clamping force at a given hydraulic pressure. Standard manual override. Actuated by hydraulic cylinders which provide high clamping preloads. Model 70 Collet Connector HC Collet Connector SD24752 SD

3 Collet Connector Comparison HC Collet Connector DWHC Collet Connector The DWHC is a high strength drilling and completion collet connector engineered for the high loads encountered in ultra deepwater applications. Features include: Segment and hub geometry and a large actuating piston area create a greater clamping force for the higher loads encountered in ultra deepwater conditions. New flange exceeds API standards with a thicker neck, a larger bolt circle and larger bolt diameter to match the capacity of the DWHC. New hub profile accommodates high load carrying capacity. This Cameron design will be shared with the industry in an effort to promote standardization and reduce total interfaces. Provides 21 million pounds total equivalent tension capacity, based on API design criteria. Design forms the foundation for the requirements of Cameron s ultra deepwater SpoolTree TM Production System applications. HCH4 Collet Connector DWHC Collet Connector SD24754 SD24755 The HC Collet Connector is similar to the popular Model 70, but is designed to provide greater preload to withstand higher separating forces. Features include: Short swallow up, tapered hub profile and positive unlocking system allow disconnection at angles up to 30. Shortest swallow up of any major wellhead connector available on the market. Large actuating piston area creates a greater preload at a given hydraulic pressure than the Model 70. Higher applied loads can be tolerated without causing hub face separation because of the higher preloads. Uses annular cylinder with greater annular piston area for larger locking and unlocking force. Compact design minimizes height and weight. HCH4 Collet Connector The HCH4 Collet Connector is based on Cameron s standard HC Collet Connector. It incorporates most major features of the standard HC Collet Connector with its standard HC operating system and structural load carrying components. Its unique locking design includes three load shoulders on the collet segments/fingers, allowing the customer to use a Cameron HC connector to lock onto an H4 wellhead and still maintain a direct load path. AX, CX and BX Gaskets Cameron subsea collet connectors utilize field-proven, metal-to-metal gaskets to ensure seal integrity. The connector s internal hub is fitted with the AX gasket, available with bonded hycar resilient rings upon customer request. The flanged, studded or clamped top connection of the connectors is fitted with either the pressure-energized CX gasket or the ring joint BX gasket. These gaskets are recessed into and retained by the clamped, studded or flanged hub, ensuring face-to-face contact with minimal clamping force. 3

4 Hub Interchangeability In addition to the standard wellhead hub, Cameron has designed a unique dual hub wellhead profile to use with the DWHC Connector. This DWHC hub allows other collet connectors to be used in applications where the loading requirements are not as severe. While the standard HC Collet Connector and the Model 70 Collet Connector locks onto the DWHC hub, the DWHC Collet Connector locks onto the standard wellhead hub. No modification to either collet connector is required. Cameron s newest collet connector, the HCH4, was designed specifically to fit on a mandrel-style hub. HCH4 Connector with H4 Hub SD DWHC HC Model 70 SD24780 DWHC Hub DWHC HC Model 70 SD Standard Hub

5 Load Paths and Performance Data A load path is the way applied loads are transmitted through the connector to the wellhead. The more direct the load path, the fewer components it travels through, yielding a stiffer, more stable connection. In turn, this stiff and stable connection directly affects resistance to hub face separation. All Cameron connectors have direct load paths which provide high resistance to hub face separation. Model 70 Load Path HC Load Path DWHC Load Path HCH4 Load Path SD24782 SD24783 SD24784 SD24785 When selecting a collet connector, factors regarding preload and structural load should be taken into consideration. For instance, the Model 70 is for applications requiring up to 245,000 lb preload. For applications requiring a higher preload of up to million lb, the Model HC is available. Both the Model 70 and HC connectors utilize the same structural capacities therefore, preload is the determining factor when choosing between the two. Cameron offers the HCH4, an HC equivalent, to fit on a mandrel-style wellhead. When even higher preload and structural load capacity is called for, the DWHC is the collet connector of choice. Cameron Collet Connector Data Typical Ratings, Normal Operating Conditions/Stresses* Performance Model 70 HC DWHC HCH4 Pressure Rating (psi/mpa) 10,000/ ,000/ ,000/ ,000/ ,000/ ,000/ pressure, 0 tension* (ft-lb) 3,645,000 4,048,000 5,293,000 11,500,000 2,961,000 1,868,000 0 pressure, 0 tension* (Nm) 4,942,000 5,488,000 7,176,000 15,591,000 4,014,000 2,533,000 10,000 psi, 0 tension* (ft-lb) 1,706,000 3,219,000 3,308,000 11,750,000 3,045,000 2,631,000 10,000 psi, 0 tension* (Nm) 2,313,000 4,364,000 4,485,000 15,930,000 4,128,000 3,567,000 10,000 psi, 2,000,000 lb tension*(ft-lb) 549,000 2,063,000 2,151,000 10,300,000 2,109,000 1,850,000 10,000 psi, 2,000,000 lb tension*(nm) 744,000 2,797,000 2,916,000 13,964,000 2,859,000 2,508,000 15,000 psi, 2,000,000 lb tension* (ft-lb) 1,161,000 9,300,000 1,145,000 15,000 psi, 2,000,000 lb tension*(nm) 1,574,000 12,609,000 1,552,000 Preload (lb) 245,000 4,385,000 5,875,000 12,000,000 4,740,000 8,352,000 Preload (N) 1,090,000 19,505,000 26,133,000 53,379,000 21,085,000 37,152,000 Load Shoulder Angle (housing/connector) 25 /25 25 /25 25 /25 25 /10 45 /0 45 /0 Maximum Release Angle **** 4 4 Water Depth Rating (feet/meters) 10,000/ ,000/3048 Connector Style (hub, collet, etc.) Collet with Hub Collet with Hub Collet with Hub Collet with Hub Collet with Hub Collet with Hub Maximum Subsea Wellhead OD (in/mm) 31.39/ / / / / / Maximum Connector OD (in/mm) 64.00/ / / / / / Swallow** (in/mm) 13.38/ / / / / / Weight (studded top) (lb/kg) 16,600/ ,600/ ,100/10,478 67,000/30,391 23,200/10,524 25,350/11,499 Operating Pressure (psi/psi) 1500/ / / / / Operating Pressure (MPa/MPa) 10.30/ / / Hydraulic Volume Required (Open) (gal/liters) 4.97/18.81*** 18.50/ / / / /94.63 Hydraulic Volume Required (Closed) (gal/liters) 4.18/ / / / / /75.70 Interchange Kit for Standard Connector Not required Not required Not required Not required Not required Not required * Ratings are based on API allowable stresses for normal design loads. ** Top of wellhead to bottom of connector. If the Hydrate seal is used, the swallow will increase by approximately 2 (50.8mm). *** Additional 2.49 gallons (9.43 liters) is necessary for secondary unlock. **** The 4 release angle limit applies to initial connector/wellhead lift off of zero to 1 (25.4mm). For greater than 1 (25.4mm) of lift off, the connector can be rotated up to 6 while clearing the wellhead. 5

6 Collet Connector Comparison The charts on the right show the loads induced by the riser system on the BOP stack components. The riser load creates both a tension and bending moment on the BOP stack as shown. In these examples, F is the force on top of the BOP stack and θ is the angle of the flex joint. As these charts indicate, the DWHC has a greater capability than the standard connector, making it a clear choice for deepwater drilling and production operations. Therefore, each connection above the DWHC in the stack needs to be strengthened in order to match the DWHC s capabilities. Case 1 shows the loads on each stack connection under a normal drilling condition of 1.5 million pounds tension and 1.88 riser angle. Case 2 shows that with the maximum bending moment capability of the DWHC connector, each connection point in the stack sees significantly higher bending moments compared to the normal drilling conditions. Flex Joint Annular BOP Collet Connector Adapter Spool Annular BOP Single BOP Double BOP Double BOP Wellhead Connector Flex Joint Annular BOP Collet Connector Adapter Spool Annular BOP Stack Loads, Case 1 Stack loads with DWHC connector under normal drilling conditions. F = 1,517,112 lb θ = 1.88 Working Pressure = 15,000 psi DWHC Max Top Tension = 2,000,000 lb FY, Top (lb) M, Top (ft-lb) 0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 Stack Loads with DWHC, Case 2 Stack loads derived from the extreme load capability of the DWHC connector. F = 2,326,828 lb θ = 5.28 Working Pressure = 15,000 psi DWHC Max Top Tension = 2,000,000 lb FY, Top (lb) M, Top (ft-lb) Single BOP Double BOP Double BOP Wellhead Connector 0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 7,000,000 8,000,000 9,000,000 10,000,000 Bending Moment Capacity (Million ft-lb) Structural Load Capacities, 10K Bore Pressures Based on membrane plus bending at yield Tension Capacity (Million lbs) Model 70 / Model HC DWHC Bending Moment Capacity (Million ft-lb) Structural Load Capacities, 15K Bore Pressures Based on membrane plus bending at yield Tension Capacity (Million lbs) Model HC DWHC 6

7 Operating Data and Dimensions C B C B A A D D Model 70 SD24786 HC SD24787 C B C B A A D D HCH4 SD24788 DWHC SD24789 Model 70 Collet Connector Bore Working Number of Stroke Fluid Requirements (gal/liters) A B C D Weight Size Pressure* Cylinders Length (in/mm) Open Closed (in/mm) (in/mm) (in/mm) (in/mm) (lb/kg) 18-3/4 10,000 psi / / / / / / / ,600/7530 *Also available in the following sizes and working pressures: 13-5/8 5000, 10,000 and 15,000 psi; 16-3/ and 10,000 psi; 20-3/ and 3000 psi; 21-1/4 2000, 5000 and 10,000 psi. HC Collet Connector Bore Working Operating Preload Fluid Requirements No Secondary Unlock Secondary Unlock Weight Size Pressure* Pressure (lb/mpa) (gal/liters) A B A B C D (lb/kg) (psi/mpa) Open Closed (in/mm) (in/mm) (in/mm) (in/mm) (in/mm) (in/mm) 18-3/4 10,000 psi 3000/ ,821,000/19, / / / / / / / ,600/9, /4 15,000 psi 3000/ ,875,000/40, / / / / / / / / ,100/10,478 *Also available in the following sizes and working pressures: 13-5/8 15,000 psi, 21-1/ psi HCH4 Collet Connnector Bore Working Operating Preload Fluid Requirements (gal/liters) A B C D Weight Size Pressure Pressure (lb/mpa) (lb/mpa) Open Closed (in/mm) (in/mm) (in/mm) (in/mm) (lb/kg) 18-3/4 10,000 psi 3000/ ,740,000/31, / / / / / / ,200/10, /4 15,000 psi 1500/10.44* 3,000,000/20, / / / / / / ,350/11,499 *At 3000 psi (20.68 MPa) operating pressure, preload is 6,140,000 lb (42,329 MPa) DWHC Collet Connector Bore Working Operating Preload Fluid Requirements (gal/liters) A B C D Weight Size Pressure Pressure (lb/mpa) (lb/mpa) Open Closed (in/mm) (in/mm) (in/mm) (in/mm) (lb/kg) 18-3/4 15,000 psi 3000/ ,000,00/82, / / / / / / ,000/30,391 7

8 Western Hemisphere Cameron PO Box 1212 Houston Texas Tel Fax Eastern Hemisphere Cooper Cameron (U.K.) Ltd. 5 Mondial Way Harlington Hayes UB3 5AR Tel Fax Asia Pacific/Middle East Cooper Cameron (Singapore) Pte. Ltd. No. 2 Gul Circle, Jurong Industrial Est Locked Bag Service No. 3 Jurong Town Post Office Singapore Republic Of Singapore Tel Fax Inconel is registered trademark of INCO. Cooper Cameron Corporation, Cameron Division, Printed in USA, 6/99, TG/5M, WR6585/TC1272