Bai giang pttkk well control and monitoring

Well Control and Monitoring System Well Control System Well Monitoring System References (CDF) Jorge H.B Sampaio Jr “Drilling Engineering Fundamentals.” Master of Petroleum Engineering Curtin University of Technology, 2007 Chapter 2 (WEC) Rabia, Hussain “Well Engineering & Construction” Entrac Consulting Limited, 2002 Chapter 16 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Well Control System 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Well Control & Kick ✓ The functions of the well control system are ➢ to detect, stop, and remove any undesired entrance of formation fluids into the borehole ✓ An undesired entrance of formation fluid into the borehole is called kick and ➢ may occur due to several reasons such as ❖ high pressure formations ❖ insufficient drilling fluid density ❖ drillstring swab ❖ loss of circulation ❖ formation fracture 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Kicks ✓ Any influx of formation fluids (oil, gas or water) in the borehole is known as a kick ✓ When a kick is taken, primary control has been lost ✓ An uncontrolled kick at the surface is called a blowout 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Causes of Kicks ✓ Kicks occur when “underbalance is found” ✓ Underbalance is caused by: ➢Increase in Formation Pressure ➢Mud Hydrostatic Reduction ✓ What causes Mud Hydrostatic to drop? Pressure = Mud Wt x Constant x TVD 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Primary, Secondary and Tertiary Well Control ✓ Primary Control ➢Mud Weight ✓ Secondary Control ➢Blowout Preventer (BOP) ✓ Tertiary Control ➢Control & Recovery 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Primary, Secondary and Tertiary Well Control ✓ The well control system is designed to: ➢Detect a kick ➢Close-in the well at surface ➢Remove the formation fluid which has flowed into the well ➢Make the well safe 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Primary Well Control ✓ Mud Hydrostatic Pressure: ➢Mud Hydrostatic Pressure > Formation Pressure 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Secondary Well Control ✓ BOP (Blowout Preventer) ✓ Secondary control is activated only to restore the primary well control 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com Tertiary Well Control ✓ Tertiary control involves pumping substances into the wellbore to try to physically stop the flow down hole ✓ This may involve pumping cement with a high risk of having to abandon the well afterwards ✓ However, there is another method that may be employed, called a Barite Plug … 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 10 Choke and Kill Manifolds ✓ Choke and kill manifolds can be made to meet any customer requirements But for optimal work, they should consist of: ➢ one, two or more drilling choke system (operated hydraulically or manual) ➢ manual and hydraulically or air operated gate valves ➢ pressure transmitters ➢ pressure gauges ➢ Crosses ➢ Tees ➢ A buffer tank as required 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 72 Choke and Kill Manifolds 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 73 Drilling Choke System ✓ Hydraulically actuated drilling chokes are available in working pressures from 34.5 to 138 MPa (5000 to 20000 psi) ➢ Inlet and outlet flange sizes from 77.8 to 103.2 mm ➢ The standard size of orifice is 44.5 mm (1 ¾”) ➢ Working temperature is up to 121 °C ➢ Hydraulic pressure of MPa (300 psi) is applied to the actuator, which results in opening or closing the choke 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 74 Drilling Choke System ✓ Manually actuated drilling chokes are available in working pressures from 34.5 to 138 MPa (5000 to 20000 psi) ➢ Inlet and outlet flange sizes from 77.8 to 103.2 mm ➢ The standard size of orifice is 44.5 mm (1 ¾”) ➢ Working temperature is up to 121 °C 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 75 Drilling Choke System ✓ Pressure transmitters, located on the standpipe and the choke manifold, use actual mud pressure as a pilot to regulate low pressure pneumatic signals which are transmitted through hoses to the control console where pressure readings are registered on the panel gauges 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 76 Gate Valves ✓ The valves used on the choke manifold are of the gate valve type Their main parts are: positive rotating seats gate and seat assembly solid gate thrust bearings threaded packing retainer back-seating stem pin grease injection port body and trim 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 77 Gate Valves ✓ The air or hydraulically operated models are identical in construction, except for the size and pressure rating of the operating cylinder 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 78 Killing a Well ✓ Simplifying the Initial Phase of Killing the well 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 80 Well Monitoring System 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 91 Data Required To Control of Operations Under Way in The Rig ✓ Several sensors, gauges, meters, indicators, alarms, and recorders exist in the rig to provide all data required to control (safely, efficiently, and reliably) of all operations under way in the rig ✓ Among the most important parameters are: ➢ weight on bit (WOB) and hook load, ➢ rate of penetration (ROP), ➢ rotary speed, ➢ torque, ➢ circulating (pump) pressure, ➢ flow rate (in and out), ➢ drilling fluid gain/loss, ➢ mud temperature, ➢ mud density, ➢ total hydrocarbon gas in the drilling fluid 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 92 Indication of Hook Load and Weight on Bit ✓ Accurate and reliable indication of hook load and weight on bit are essential for ➢ the efficient control of rate of penetration, bit life, borehole cleaning, and borehole direction ✓ The weight indicator works ➢ in conjunction with the deadline anchor ➢ using either tension or compression hydraulic load cells ➢ The deadline anchor senses the tension in the deadline and hydraulically actuates the weight indicator ✓ Most weight indicators have two hands and two scales ➢ The inner scale shows the hook load and the outer one shows the weight-on–bit 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 93 Weight Indicator and A Deadline Anchor 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 94 Weight-on-bit ✓ To obtain the weight–on–bit, the driller perform the following steps: ➢ with the bit out of the bottom, the drillstring is put to rotate and the weight of the drillstring is observed in the central scale;, ❖ using the knob at the rim of the weight indicator, the outer scale is adjusted so that the zero of the outer scale aligns with the longer hand ➢ The driller lowers the drillstring slowly observing the long hand ❖ When the bit touches the bottom, part of the weight of the drillstring is transferred from the hook to the bit (the weight–on–bit.) ❖ The amount of weight transferred corresponds to the decrease of hook load, indicated by the long pointer (turning counterclockwise) 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 95 Control Consoles ✓ All modern rigs have control consoles that ➢ shows all pertinent parameters in analog and or digital displays ✓ All parameters and operations may be ➢ recorded in physical (paper) or ➢ magnetic media for post analysis ✓ Some automated operations like ➢ constant weight–on–bit and ➢ constant torque are possible in most rigs 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 96 Drilling Control Console 01/2018 Đinh Công Vĩnh Luân – MSc in Offshore Engineering Email: luandcv@gmail.com 97