BLOWOUT PREVENTERWhy Blowout Preventer are used?• Kick : An influx of formation fluid into the wellbore• Blowout : An uncontrolled flow of well fluids and/or formation fluid from the wellbore or into lower pressured sub-surface zones (underground blowout)• Blowout Preventer : An assembly of valves attached to the casing head that allows the well to be sealed to confine the well fluids in the wellbore. Blowout preventer are of two types- i) Annular BOP ii) Ram BOP
CRITERIA FOR SELECTION OF BOP Selection of BOP determined by the following factors:• Maximum anticipated surface pressure.• Size of casing, casing hanger, bit and other drilling tools tobe lowered through the BOP stack.• Space available between top of cellar pit and bottom ofrotary table.• Matching flange connection according to the size andpressure rating of wellhead flange.• Service conditions.
BOP SPECIFICATIONStandard Sizes of BOP: 71/16”, 9”, 11”, 135/8”, 16¾”, 18¾”, 21¼”, 26¾”, 28”,291/2”, 30”Size refers to - ID, Nominal Diameter, Through boreRated Working Pressure (RWP): 2M, 3M, 5M, 10M, 15M, 20M The maximum pressure that the equipment can withstand(contain) and control. Shell Test or Manufacturer Test or Body Test:•Only once in the factory•2M, 3M, 5M – 2 TIMES the RWP•10M and above – 1.5 TIMES the RWP
BOP SPECIFICATION• Closing Ratio = Well Bore Pressure Pr. Required to close RWP• Min. Pr. Required to close = Closing Ratio• Opening Ratio Well Bore Pressure = Pr. Required to open RWP• Min. Pr. Required to open Opening Ratio =
RAM BOP• Ram Preventers are designed to seal the annulus by forcing two front packing elements which make contact with each other and seal around the object in the well bore.• Pipe Ram : It seals around the well bore and the fixed size of pipe.• Blind Ram : It seals around the well if no pipe in the well bore.• Variable Bore Ram : It seals around several pipe sizes depending on the range of variable bore ram.• Shear Ram : It shear the pipe in the well and seal the wellbore simultaneously.
BASIC BOP OPERATION
CLOSING OF RAM BOPTop seal energized by well borepressure at sealing surface of theram body Front packer sealing against pipe Opening Closing chamber chamber Well Pressure
CLOSING OF RAM BOP TOP SEAL STEEL PLATE STEEL PLATE PUSHED BY OTHER SIDE PACKER STEEL PLATESRAM BLOCK PACKER RUBBER Well Pressure
ANNULAR BOPA large circular valve used to control wellbore fluid.• Rounded Elastomer with reinforced steel segments• Deforms the rubber radially inwards and seals• Can close around different shapes such as square andhexagonal kelly, drill collars, tool joint etc including wire line.• Can not close on stabiliser, bit and under reamer.• Can close on open hole.
ANNULAR BOPPiston Indicator Hole Wear Plate Element Segment Packing Element Latched Head Opening Chamber Piston Closing Chamber Piston Seals
FUNCTION TEST•Performed to verify the component’s intendedoperations•The test should be conducted when the drill string isinside casing•Function test should be carried out alternatively frommain control unit/derrick floor panel/auxiliary panel•Actuation time of each equipment should be withinthe limits specified by API RP53•Recorded final accumulator pressure after all thefunctions should not be less than 1200 psi or 200 psiabove the pre charged pressure of accumulator whichever is maximum•At least once in a week
FUNCTION TEST PROCEDURE•Record initial Accumulator pressure•Turn off both electric and pneumatic pumps•Close Annular BOP and Pipe Ram BOP andopen HCR one by one•Wait till pressure is stabilized•Record the closing time (closing time starts fromturning the control lever till pressure stabilized)•Turn on electrical/Pneumatic pump and open allthe preventer•Record the opening time•Record final Accumulator pressure•Record all the results in the prescribed format
BOP FUNCTION TEST REPORTRIG DATEWELL PROJECTBOP STACK DETAIL1. Annular BOP2. Single & Double ram type BOP3. Upper pipe ram size4. Lower pipe ram sizeSl. No. Description Function Time Accumulator Accumulator Remarks Initial Pressure Final Pressure1. Annular2. Lower pipe3. Upper pipe4. Blind/Shear5. Hyd. Valve on Choke line6. Hyd. Valve on kill line
BOP PRESSURE TEST (i) Low Pressure Test : 200 – 300 psi should be applied for a lowpressure test and the period is at least 5 minutes.(ii) High Pressure Test : High pressure test for RAMS and auxiliary equipment High pressure test to rated working pressure of RAMS BOP andauxiliary equipment OR rated working pressure of your wellhead. Selectthe lower number. For example, you BOP is rated for 5000 psi and yourwellhead is rated for 3000 psi. Your high pressure test for the RAMSBOP and auxiliary equipment must be only 3000 psi. Pressure duration at least 5 minutes.High pressure test for Annular Preventer High pressure test should apply to 70% of rated working pressure orRAMS test pressure. Select the lower number. For example, you testyour ram at 3000 psi and the annular working pressure is 5000 psi. Youneed to test your annular to 3000 psi (70% of annular RWP is 3500psi).Pressure duration at least 5 minutes.
BOP PRESSURE TESTPRESSURE TEST•To check the integrity of all the joints in BOP stack,BOP seals and Valves.•Clear water is considered as the best test fluid•A stable low test pressure as well as stable high testpressure should be maintained for at least 5minutes.PRESSURE TEST FREQUENCY•Prior to Spud or upon Installation•After repairs – Limited to the affected component•Not to exceed 21 Days
PRESSURE TESTINGCUP TESTER TEST PLUGThe cup of the tester gives Designed to seat in well headeffective sealing in the casing and sealLimited to 70-80% of the burst Can be tested up to RWP ofof upper part of casing Ram BOPYield strength of drill pipe Different makes of well headmay limit the test pressures. have different types of testrams plugsCan not be used to test blind/ Blind/ Shear Blind Rams canshear blind be tested.
BOP PRESSURE TEST1. Run-in 2-3 stands of HWDP2. Make-up Test Plug3. Make-up 1 single of 5” D/P4. Make-up Kelly5. Open McEvoy valve and keep it in open position6. Make-up 2” hole fill-up line7. Close Annular or Ram BOP (whichever is tested)8. Flushed all the lines(through choke manifold)9. Start pump and raise pressure to 200 psi10. Wait for at least 5 mins, observe if any pressure drop.11. If positive, check for any leakage12. If negative, increase pressure to 300 psi13. Repeat step 10 and 11, if negative14. Increase pressure in increment of 100 psi up to the desired value and repeat step 10 and 11 after every increment15. Record the test readings16. Bleed off pressure.
PROJECT: TEST FLUID- WATER/NITROGEN WELL NO.:RIG: DATE:TEST EQUIPMENT- TEST PUMP/CEMENTING UNITSl. TYPE OF BOP TEST PRESSURE & DURATION RemNo. Low Pressure Duration High Pressure Duration arks Annular BOP Upper pipe ram Lower pipe ram Blind/Shear ram Choke manifold Kill manifold Hyd Valve on choke line Hyd Valve on kill line HP Valves on choke & kill manifold UKC LKC FOSV Inside BOP
IMPORTANT POINTS• Prior to conducting Pressure Test inform every single person on Rig i.e. Pre-operation meeting• Do not allow any person to go near cellar area or below derrick floor• Before conducting test, discuss with DIC• Take care test plug properly sit on well head, preferably test plug and well head make are same.• Make sure McEvoy valve is opened before conducting test, as casing will get pressurized if closed and leakage is there.• Anchor 2” hole fill-up line properly before conducting test• Conduct test in presence of at least one experience person• If pressure test is conducted with test plug, take care of Riser(as test plug might get stuck during pulling out). Conduct test, if possible before R/up of Riser.