Floating & Guiding Equipment

Transcription

1 Last Revision: FEBRUARY 3, 2015 Floating & Guiding Equipment Floating equipment is commonly used on the lower sections of the casing to reduce derrick stress by allowing the casing to be floated into place. The weight of the casing on holes of moderate to deep depths can cause tremendous strain on the derrick. When the casing is immersed in the well fluid, it is buoyed by force equal to the weight of the fluid that the casing displaces. If the casing is allowed to fill as it is lowered, the buoyancy will be equal to the weight of the fluid displaced by its wall. Should the casing not be allowed to fill, a greater amount of fluid is displaced by the casing string and the weight on the derrick is less. The guide shoe directs the casing away from ledges and minimizes sidewall caving as the casing passes through deviated sections of the hole. Some basic types of floating and guiding equipment are (1) the guide shoe, with or without a hole through the guide nose, (2) the float shoe containing float valve and guide nose, and (3) the float shoe and float collar containing and automatic fill-up valve. The simplest guide shoe is an open-end collar, with or without a molded nose. It is run on the first joint of casing and simply guides the casing past irregularities in the hole. Circulation is established down the casing and out the open end of the guide shoe, or through side ports designed to create more agitation as the cement slurry is circulated up the annulus. If the casing rests on bottom or is plugged with cuttings, circulation can be achieved though the side ports. A modified guide shoe with side ports may aid in running the casing into a hole where obstructions are anticipated. This tool has side ports above and a smaller opening through the rounded nose. The smaller opening ensures that approximately one-half the fluid is pumped through the existing side ports. These ports will help wash away obstructions that may be encountered and will also aid in getting the casing to bottom if some of the cutting have settled in the bottom hole. When wells accumulate enough cuttings on the bottom to cause a drop in pumping efficiency and an increase in pumping pressure, a high side port guide shoe can be installed on the casing shoe to help remove these cuttings. This equipment is particularly suitable to areas where large accumulations of the cuttings make it difficult to determine when casing touchdown is accomplished. The jetting action of the side port tool types aids in removing the cuttings and helps provide a cleaner wellbore with increased turbulence during circulation and cementing. It can also aid in the uniform distribution of the slurry around the shoe. If the casing is set on the bottom and no fluid can exit through the bottom of the tool, then the side ports can enable circulation to be established. The combination guide or float shoe usually incorporates a ball or spring-loaded backpressure valve. The outside body is made of steel of the same strength as that of the casing. The backpressure valve is enclosed in plastic and highstrength concrete. The valve, which is closed by a spring or by hydrostatic pressure from the fluid column in the well, prevents fluids from entering the casing while pipe is lowered into the hole. Suspension is controlled by the volume of fluid placed inside the casing by filling either from the surface or through a fill-up device in the float shoe. Once the casing has been run to the desired depth, circulation is established through the casing and float valve and up through the annulus. When the cement job is completed, the backpressure valve prevents cement from flowing back into the casing. 1

2 For shallow wells where it is not necessary to guide or float the casing to bottom, a simple casing shoe is used. Float collars are normally placed one to three joints above the float or guide shoe in the casing string and serve the same basic functions as the float shoe. They contain a backpressure valve similar to the one in the float shoe and provide a smooth surface or latching device for the cementing plugs. The space between the float collar and the guide shoe serves as a trap for contaminated cement or mud that may accumulate from the wiping action of the top cementing plug. The contaminated cement is thus kept away from the shoe, where the best bond is required. When the cement plug seats at the float collar, it shuts off fluid flow and prevents over pumping o the cement. A pressure buildup at the surface indicates when cement placement is complete. For larger casing, float collar or shoes may be obtained with a special stab-in device that allows the cement to be pumped through tubing or drill pipe. (This method of placement is often called inner-string cementing.) Such a device eliminates the need for large cementing plugs and oversize plug containers. It also reduces the volume of cement that can be lost if the job must be terminated before all the slurry is mixed and pumped. For reason of economy, simple insert flapper valve and seat may be installed in the casing string one or two joints above the guide shoe. This insert valve is designed for use in wells down to 7,000 ft. and for pressures less than the collapse pressure of J-55 casing in the particular weight range being used. The backpressure valve in automatic fill-up equipment is held out of service until it is release by a predetermined pump pressure or flow rate applied from the surface. The rate of the flow into the casing is usually low enough to hold the fluid level within 10 to 300 ft. of the surface. The backpressure valve in automatic fill-up equipment is held out of service until it is release by a predetermined pump pressure or flow rate applied from the surface. The rate of the flow into the casing is usually low enough to hold the fluid level within 10 to 300 ft. of the surface. When purchasing floating equipment, it is important to specify the OD, the threading, the material grade, and the pipe weight. 2

3 Super Seal II All casing-size Super Seal II float collars include an auto fill feature. This feature, installed between the valve and pressure seat, is deactivated by flow rate. The auto fill feature allows wellbore fluids to enter the casing from the first joint, reducing surge pressure on the formation and reducing casing fill time from the surface. When the auto fill feature is pumped loose with a high fluid rate, the float valve is returned to a dependable Super Seal II backpressure valve. The auto fill feature will deactivate if the flow through the valve reaches a predetermined rate. The Super Seal II float collar includes the Super Seal II backpressure valve, which prevents cement pumped into the casing/wellbore annulus from re-entering the casing ID after cementing operations. PDF (Pressure Differential Fill) Pressure Differential Fill (PDF ) float collars and shoes allow operators to maintain a constant fluid height inside the casing of a well. As fluid is allowed to enter through the bottom of the casing, the system maintains a constant differential pressure between the inside and outside of the casing at the floats to ensure constant fluid height within the casing. PDF floating equipment is supplied in the differential fill mode and is ready to be RIH. After all casing runs have been completed, the differential fill option is deactivated by dropping a weighted plastic ball from the surface and pumping the ball through the tool. A spring-loaded valve in the fill-up unit regulates filling. When hydrostatic pressure outside the casing exceeds the spring tension, fluid is allowed to enter the casing; when pressure inside the casing combines with spring tension to exceed the pressure outside the casing, the valve closes. The differential pressure between the inside and outside of the casing is the sum of the spring rates of all PDF floating equipment in the casing string. The hole may be circulated at any time while casing is run without affecting the fillup unit. After the ball passes the float collar and/or shoe, the PDF valve is converted to a one-way cementing valve that allows cement to flow into the annulus, where it is prevented from reentering the casing. PDF floating equipment should not be used in wells deviated more than 30 from vertical. PDF equipment cannot be used with Super Seal II floating equipment. 3

4 Last Revision: FEBRUARY 2, 2015 Super Seal II Collar & Shoe Casing OD Casing Weight Tool OD Minimum ID Length in. lb./ft. in. in. in. 4 1/ / /8 8 5/8 9 5/8 10 3/4 11 3/4 13 3/ Thread Type Different casing grades, weights, threads, valve configurations, and non-rotating valve features are available. API proprietary threading and PREMIUM threading available upon request. PDF (Pressure Differential Fill) Collar & Shoe Casing OD Casing Weight Tool OD Minimum ID Length in. lb./ft. in. in. in. 4 1/ / /8 8 5/8 9 5/8 10 3/4 11 3/4 13 3/ Thread Type Different casing grades, weights, threads, valve configurations, features are available. API proprietary threading and PREMIUM threading available upon request. 4

5 VersaFlex Landing Collar Insert 13 Al Aluminum The VersaFlex plug assembly is designed to be used in conjunction with a landing collar. The VersaFlex plug assemblies and landing collars have been designed for the most common casing sizes. Uniquely designed to mate with the VersaFlex plug assembly. The specially designed landing collar helps ensure a positive seal is created when plug bump is achieved and is primarily available in P- 110 or P-110/Q-125 grades. 5

6 13 Al Aluminum Enclosed Down-Jet Special Nose Options 13 Al Aluminum 13 Al Aluminum Tapered Down-Jet Tapered Offset Round Down-Jet 6

7 Tungsten Carbide Reamer Shoe 6 C Carbon 74 W Tungsten Casing Size Hole Size in. in. 5 7/ /2 6 1/4 7 7/8 6 1/ /8 6 1/2 5 1/2 7 7/ /2 8 1/2 7 5/8 9 7/8 9 5/8 12 1/4 14 3/4 13 3/ /2 Extended-length stabilizer blades designed to reduce casing vibration or whirl while reaming and reliable standoff during cementing. While running casing in the well, the cutting structure contacts the wellbore to the specified diameter (accommodating couplings and attachments) to help land the casing to depth.. Back reaming cutting structure is a standard feature of the SV and RPT reamer shoe. Drillable and no drillable tapered noses help ensure casing follows the wellbore to the desired setting depth. Tapered composite nose with new rounded profile is the standard option for SV reamer shoes. Enclosed down-jet configuration is standard for SV reamer shoes. Steel case designed to P-110/Q-125 equivalent as a standard. 4 1/4-in. Super Seal II valve for 7-in. assemblies and larger. 2 3/4-in. Super Seal II valve in assemblies smaller than 7 in. 7

8 Cementing Plugs Unless a well is drilled with air or gas, the casing and hole are usually filled with drilling fluid before cementing. To minimize contamination of the interface between the mud and the cement in the casing, a bottom plug is pumped ahead of the cement slurry. This plug wipes the mud from the casing wall as it moves down the pipe. When it reaches the float collar, differential pressure ruptures a diaphragm on top of the plug, allowing the cement slurry to flow through the plug and the floating equipment and up the annular space between the pipe and the hole. The top cementing plug is landed at the float collar or float shoe. It keeps the displacement fluid from channeling with and contaminating the cement slurry and cause a pressure buildup in the pipe. Although top and bottom plugs are similar in outward appearance, their internal structures are different. The top plug, with its drillable insert and rubber wipers, is built to withstand the force of the cement column and displacement fluid and to provide dependable sealing or shutoff when it lands on a collar, baffle plate, or shoe. The bottom plug is fitted with a diaphragm in its top that will rupture at about 200 to 400 psi, thereby allowing the cement to be pumped through the floating equipment, down the casing, and into the annular space. The burst pressure of the diaphragm is high enough to prevent premature rupture before the plug lands. The bottom plug usually molded out of a different color so that the top plug may be readily distinguished from the bottom plug. For cable tool operations, plugs are made with plastic inserts to reduce drilling time. There are times when a bottom plug is not desired. In these cases, water or chemical flush should precede the cement slurry to clean the casing of the mud solids. This is not as effective as the mechanical wiping action of the bottom plug, but it will reduce the amount of contaminated slurry. The top plug follows the cement slurry, wiping it from the casing wall. 8

9 Five Wiper is designed to provide fluid separation during displacement and wiping efficiency for wiping wellbore casing and tubular clean of drilling mud, spacers, and cement. Non-Rotating plugs have added locking teeth that prevent the equipment from spinning during drill out, which reduces drill out times And associated rig costs. HWE (High Wiping Efficiency) top and bottom cementing plugs are designed to help Improve wiping efficiency during cementing operations. The wipers of the HWE plug are a deep-cup design, which provides greater wiping efficiency to remove mud cake, mud film, rust, and mill scale. 9

10 Five Wiper Specifications Casing OD Casing Weight Length OD ID in. in. in. in. in. 3 1/ to / to to / to to / to / to / to / to / to to / to Non-rotating five wiper plugs are available for casing 7 in. to 20 in. only. Five wiper plugs are available for WBM, OBM, and SBM systems. Available top and bottom plastic and aluminum insert bodies. Bottom plugs have a 350 psi rupturable diaphragm. HWE (High Wiping Efficiency) Specifications Casing OD Casing Weight Min. / Max. ID Length OD ID in. in. in. in. in. in. 4 1/ to / to / / to / to / / to / / to / / to / / to / HWE plugs are available for WBM, OBM, and SBM systems. New rubber and phenolic plastic designs offer increased drill out benefits with smaller debris, tighter gripping, and easier drill out than five wiper plugs. HWE plugs are suitable up to 400 F. The bottom plug is supplied with a 750 psi rupture disk. 10

11 Casing Centralizers The uniformity of the cement sheath around the pipe determines to a great extent the effectiveness of the seal between the wellbore and the casing. Since holes are rarely straight, the pipe will generally be in contact with the wall of the hole at several places. Hole deviation may vary from zero to -in offshore directional holes- as much as 70 to 80. Such severe deviation will greatly influence the number and spacing of centralizers. A great deal of effort has been expended to determine the relative success of running casing strings with and without centralizers. Although authors differ about the proper approach to an ideal cement job, they agree unanimously that success hinges on the proper centralization of casing. Centralizers are among the few mechanical aids covered by API specifications. When properly installed in gauge sections of a hole, centralizers prevent drag while pipe is run into the hole, center the casing in the wellbore, minimize differential sticking, and thus help to equalize hydrostatic pressure in the annulus, and reduce channeling and aid in mud removal. Two general types of centralizers are spring-bow and rigid. The spring-bow type has a greater ability to provide a standoff where the borehole is enlarged. The rigid type provides a more positive standoff where the borehole is to be gauged. Special close-tolerance centralizers may be used on the liners. The important design considerations are positioning, method of installation, and spacing. Centralizers should be positioned on the casing through intervals requiring effective cementing, on the casing adjacent to (and sometimes passing through) the intervals where differential-sticking is a hazard, and occasionally on the casing passing through doglegs where key seats may exist. Effective cementing is important through the production intervals and around the lower joints of the surface and intermediate casing strings to minimize the likelihood of joint loss. The centralizers are held in their relative position on the casing by either the casing collars or mechanical stop collars. The restraining device (collar or stop collar) should always be located within the bow-spring-type centralizer so the centralizer will be pulled - not pushed - into the hole. 11

12 Therefore, the bow-spring-type centralizer should not be allowed to ride free on a casing joint. All casing attachments should be installed or fastened to the casing by some method, depending on the type-i.e., solid body, split body, or hinged. If they are not installed over a casing collar, then a clamp must be used to secure or limit the travel of the various casing attachments. There are a number or different types of clamps. One type is simply a friction clamp that uses a set screw to keep the clamp from sliding. Another type uses spiral pins driven between the clamp and the casing to supply the holding force. Other have dogs (or teeth) on the inside that actually bite into the casing. Any clamp that might scar the surface of the casing could be considered unusable where corrosion problem exist. One of the little-emphasized benefits of centralizers is that they reduce pipe sticking caused by pressure differentials. The force holding casing against a permeable section in the hole is proportional to the pressure differential across the pipe and to the area of the pipe in contact with the wellbore isolated from the hydrostatic pressure by thickened mud cake. The design of centralizers varies considerably, depending on the purpose and the vendor. For this reason, the API specifications cover minimum performance requirements for standard and close-tolerance spring-bow casing centralizers. They are not applicable to rigid or positive centralizers. 12

13 Standard is specially designed for vertical wells where low starting forces as well as high restoring force are required. The bows of these centralizers are heat treated in a special furnace which gives it the particular bow spring action. The flexing of the bows is a critical factor for these centralizers and the bows undergo a special state of flexing before assembly to ensure that they do not snap off under extreme stress conditions. Standard with Turbo Fins has turbo fins designed to deflect the fluid flow in a turbulent and outward directed spiral. Standard Latch On Casing OD Hole ID Nominal OD Height Bows MEGO AFEK in. in. in. in. no. Part No. 2 7/8 6 1/8 6 1/4 22 1/2 4 CEF / /4 4 CEF /2 6 1/8 6 1/8 22 3/4 4 CEF /2 6 1/4 6 3/4 22 3/4 4 CEF / /2 22 1/2 4 CEF /2 6 1/8 6 1/ CEF /2 15 1/2 41 1/2 4 CEF / CEF / CEF CEF /2 6 3/ CEF /2 8 1/2 8 1/ CEF /2 8 3/4 9 1/ CEF /2 9 1/2 22 3/4 4 CEF /4 8 3/ CEF /8 9 1/ CEF /8 9 7/8 10 1/ CEF /8 12 1/ CEF /8 12 1/ /2 6 CEF /8 12 1/ CEF /8 14 1/2 14 3/ CEF /8 14 3/ CEF /8 12 1/4 12 3/8 22 3/4 6 CEF Sizes not provided on manual can be built upon request. 13

14 Standard Latch On Casing OD Hole ID Nominal OD Height Bows MEGO AFEK in. in. in. in. no. Part No. 10 3/4 12 1/4 14 1/ CEF /4 14 3/4 14 3/ CEF /4 14 3/4 14 3/4 22 3/4 6 CEF /8 17 1/2 18 1/ CEF /8 17 1/2 18 1/ CEF / /2 6 CEF /4 18 1/ CEF /2 18 1/ CEF CEF /4 8 CEF /4 8 CEF CEF CEF / CEF CEF / CEF / CEF / CEF30-36 Standard with Turbo Fins Latch On Casing OD Hole ID Nominal OD Height Bows MEGO AFEK in. in. in. in. no. Part No. 3 1/2 6 1/8 6 1/ CEF TF 3 1/2 4 3/4 4 3/ CEF TF 3 1/2 6 1/4 6 1/ CEF TF 4 1/2 6 7/8 7 1/ CEF TF 4 1/ / CEF412-7TF 5 1/2 6 1/2 6 5/ CEF TF 7 5/8 8 1/2 8 3/ CEF TF 9 5/8 10 5/8 10 7/ CEF TF 9 5/8 12 1/ CEF TF 9 7/8 12 1/4 12 3/ CEF TF 13 3/8 17 1/ CEF TF 13 5/8 17 1/ CEF TF /2 18 3/ CEF TF CEF20-26TF Sizes not provided on manual can be built upon request. 14

15 Slip-On In this type of centralizers the end collars do not have any hinges hence these centralizers can be slip on to the casing. Standard Slip On Casing OD Hole ID Nominal OD Height Bows MEGO AFEK in. in. in. in. no. Part No. 3 1/2 6 1/8 6 1/ CEF SLIPON 3 1/2 4 3/4 4 3/ CEF SLIPON 3 1/2 6 1/8 6 1/ CEF SLIPON 4 1/2 6 7/8 7 1/ CEF SLIPON 4 1/ / CEF412-7SLIPON 5 1/2 6 1/2 6 5/ CEF SLIPON 7 5/8 8 1/2 8 3/ CEF SLIPON 9 5/8 10 5/8 10 7/ CEF SLIPON 9 5/8 12 1/ CEF SLIPON 9 7/8 12 1/4 12 3/ CEF SLIPON 13 3/8 17 1/ CEF SLIPON 13 5/8 17 1/ CEF SLIPON /2 18 3/ CEF SLIPON CEF20-26SLIPON Sizes not provided on manual can be built upon request. 15

16 Close Tolerance is a liner centralizer designed for close tolerance applications where running drag must be minimized paired with highest possible centering strength. Casing OD Hole ID Nominal OD Height Bows MEGO AFEK in. in. in. in. no. Part No. 4 1/2 6 3/ CEF SLIPONTC 9 5/8 10 5/8 10 7/ CEF SLIPONTC 13 3/8 14 3/4 15 1/ CEF SLIPONTC /2 17 3/ CEF SLIPONTC Sizes not provided on manual can be built upon request. Dual Contact can be used in deviated wells which require low running forces. These are designed to pass through tight spots and doglegs. The double bow design makes these centralizers act as rigid centralizers under high side loads. Casing OD Hole ID ID OD Height MEGO AFEK in. in. in. in. in. Part No. 5 1/2 8 1/2 5 5/8 8 1/2 25 1/2 9 5/8 12 1/4 9 3/4 12 5/8 25 1/2 CEF DC CEF DC Sizes not provided on manual can be built upon request. 16

17 Positive Bar provides positive standoff and centering, and can be used in both cased or open hole applications. Designed for use in highly deviated and horizontal well conditions, and offers sufficient clearance for fluid passage, maximum flow and well bore stabilization. Turbo For more demanding wells the Turbo is available in a heavy duty version with spiral blades to provide swirl action to the cement slurry. Casing OD Hole ID OD ID Height MEGO AFEK in. in. in. in. in. Part No /2 8 1/4 7 1/8 7 1/4 CER7-812ALE 9 5/8 12 1/ /4 7 1/4 CER ALE 9 7/8 12 1/ /4 CER ALE Sizes not provided on manual can be built upon request. 17

18 Friction will provide the sliding limits according to API RP 10D-2. Casing OD Maximum Holding Screw OD Force up MEGO AFEK in. in. in. lb. Part No. 3 1/2 5 3/8 x 2 3/4 7,000 CO312FS 5 1/2 7 3/8 x 2 3/4 7,000 CO512FS 7 8 1/4 3/8 x 2 3/4 7,000 CO7FS 7 5/8 9 1/8 3/8 x 2 3/4 7,000 CO758FS 9 5/8 11 1/8 3/8 x 2 3/4 7,000 CO958FS 10 3/4 12 1/4 3/8 x 2 3/4 7,000 CO1034FS /8 3/8 x 2 3/4 7,000 CO16FS /8 x 2 3/4 7,000 CO20FS /2 3/8 x 2 3/4 7,000 CO22FS FASGRIP with dogs design with case hardened inserts embedded in collar ID to provide maximum holding resistance. Casing OD Minimum Holding Force Dogs MEGO AFEK Hole Size Up in. in. Quantity lb. Part No. 2 7/8 4 5/8 2 40,000 CO278FG 3 1/2 5 1/8 2 40,000 CO312FG 4 1/ ,000 CO412FG 5 6 1/2 2 40,000 CO5FG 5 1/ ,000 CO512FG 7 8 1/2 4 40,000 CO7FG 7 5/8 9 1/4 4 40,000 CO758FG 9 5/8 11 1/8 6 40,000 CO958FG 9 7/8 11 3/8 6 40,000 CO978FG 10 3/4 12 3/8 6 40,000 CO1034FG 11 3/4 13 1/4 6 40,000 CO1134FG 13 3/8 14 7/8 6 40,000 CO1338FG ,000 CO16FG ,000 CO20FG ,000 CO22FG ,000 CO28FG ,000 CO30FG Sizes not provided on manual can be built upon request. 18

19 Slip-On offers superior holding capability in close tolerance conditions and where extreme loading may occur. Casing OD Maximum OD HEXSOC Set Screw (Cup Point) Screws Holding Force Up MEGO AFEK in. in. in. Quantity lb. Part No. 3 1/2 4 3/8 1/2 x 3/8 4 20,000 CO312SLIPON 4 1/2 5 3/8 1/2 x 3/8 4 20,000 CO412SLIPON 5 1/2 6 3/8 1/2 x 3/8 5 20,000 CO512SLIPON 7 7 7/8 1/2 x 3/8 6 20,000 CO7SLIPON 7 5/8 8 1/2 1/2 x 3/8 6 20,000 CO758SLIPON 9 5/8 10 3/4 1/2 x 3/8 6 20,000 CO958SLIPON 9 7/8 10 7/8 1/2 x 3/8 6 20,000 CO978SLIPON 13 3/8 14 5/8 1/2 x 3/8 6 20,000 CO1338SLIPON 13 5/8 14 5/8 1/2 x 3/8 7 20,000 CO1358SLIPON /4 1/2 x 3/8 8 20,000 CO16SLIPON /4 1/2 x 3/ ,000 CO20SLIPON Sizes not provided on manual can be built upon request. Seamless Casing OD Minimum Hole Size Screws HEXSOC Set Screw (Cup Point) MEGO AFEK in. in. Quantity in. Part No. 5 1/2 6 3/8 5 1/2 x 1/4 CO512SLESS 7 7 7/8 6 1/2 x 1/4 CO7SLESS 13 5/8 14 5/8 6 1/2 x 3/8 CO1358SLESS Sizes not provided on manual can be built upon request. 19

20 MEGO AFEK USA 5800 S. 42nd St., Suite E McAllen, Texas +1 (956) (956) sales@mego-afek.com MEGO AFEK MEX Reynosa, Tamaulipas +52 (899) (899) ventas@mego-afek.com Poza Rica, Veracruz +52 (782) ventas@mego-afek.com MEGO AFEK VEN Maracaibo, Zulia +58 (261) (261) (261)