Oil & Gas Production and Surface Facilities
- 1. Oil & Gas Production and Surface Facilities Presented by Eng. Mohamed Ibrahim 6th March 2015
- 2. Outlines Introduction Well Types at Production Phase Well Head Components Casing Head Tubing Head & SCSSV Christmas Tree Hook-up & Flow Line Components Flow Line Sizes & Schedules Flow Line Material Flow Line Flanges Flow Line Valves Gas Well Hook-up Components
- 3. Introduction The oil and gas industry is usually divided into three major sectors: upstream, midstream and downstream. The upstream sector : includes the searching for potential underground crude oil and natural gas fields, drilling of exploratory wells, and subsequently drilling and operating the wells that recover and bring the crude oil and/or raw natural gas to the surface. The midstream sector : involves the transportation (by pipeline, rail, barge, oil tanker or truck), storage, and wholesale marketing of crude or refined petroleum products. Pipelines and other transport systems can be used to move crude oil from production sites to refineries and deliver the various refined products to downstream distributors. The downstream sector : commonly refers to the refining of petroleum crude oil and the processing and purifying of raw natural gas as well as the marketing and distribution of products derived from crude oil and natural gas. The downstream sector touches consumers through products such as gasoline or petrol, kerosene, jet fuel, diesel oil, heating oil, fuel oils, lubricants, waxes, asphalt, natural gas, and liquefied petroleum gas
- 4. Well Types At Production Phase 1. Oil Wells a. Naturally Flow Producing Wells b. Artificial Lift Wells ESP Wells Beam Pump Wells Jet Pump Well Gas Lifted Wells 2. Gas Wells 3. Water Injection Wells
- 5. Naturally Flow Producing Wells A well in which the formation pressure is sufficient to produce oil at a commercial rate without requiring a pump. Most reservoirs are initially at pressures high enough to allow a well to flow naturally. A throttling valve located at the wellhead reduces pressure and regulates the flow of product to the collection site. The free flowing well can be shut-in until corrective measures are taken if problems are indicated.
- 6. Artificial Lift Wells It is the use of additional energy to produce reservoir fluids (original reservoir pressure not sufficient to produce it or optimize the produced reservoir fluids flowing rates below allowable or forecasted). The selection of the Artificial Lift Method depends on the following factors : Fluids volumes Well depth Expected GLR Tubular size Hole deviation Solids (sand,…) corrosive materials The Methods of the Artificial Lift are as follow : ESP (Electric submersible pump) Wells Beam Pump Wells Jet Pump Wells Gas Lifted Wells
- 7. Relative advantages of artificial lift methods Rod Pumps Electric Submersible Pump Jet Pump Gas Lift -Simple , basic design -Unit easily changed -Simple to operate -Can achieve low BPD -Can lift high viscous oils -Extremely high Volume -Down-hole telemetry available -Tolerant high well deviation / doglegs -Corrosion / scale Treatment possible -High volumes -Can use water as power fluid -Tolerant high well Deviation / doglegs -Solid tolerant -Large volumes -Simple maintenance -Tolerant high well Deviation / doglegs -Tolerant high GOR Reservoir fluids -Wire-line maintenance
- 8. Relative disadvantages of artificial lift methods Rod Pumps Electric Submersible Pump Jet Pump Gas Lift -Pump wear with solids Production (sand, wax) -Free gas reduces pump efficiency -Down-hole corrosion inhibitor difficult -Heavy equipment for Offshore use -Not suitable for Low volume wells -Full work-over required To change pump -Cable susceptible to damage during Installation with tubing -Cable damaged at high temperatures -Gas and solid intolerant -Sensitive to change in Surface flow-line Pressure -Free gas reduces pump efficiency -Power oil systems hazardous -Lift gas may not be available -Not suitable for viscous crude oil or emulsions -High gas pressure inside casing
- 9. Water Injection Wells Water injection or water flooding refers to the method in the oil industry where water is injected into the reservoir, usually to increase pressure and thereby stimulate production. Water injection wells can be found both on- and offshore, to increase oil recovery from an existing reservoir. Water injection Program is achieved by drilling a water well (Source) and water Injector well (Receiver) to increase the pressure & the production of a certain well.
- 10. Well Head The wellhead consists of the pieces of equipment mounted at the opening of the well to manage the extraction of hydrocarbons from the underground formation. It prevents leaking of oil or natural gas out of the well, and also prevents blowouts caused by high pressure. Formations that are under high pressure typically require wellheads that can withstand a great deal of upward pressure from the escaping gases and liquids. These wellheads must be able to withstand pressures of up to 20,000 pounds per square inch (psi). The wellhead consists of three components: A- The casing head (Including casing hangers & Casing head spool) B- The tubing head (Including Tubing hangers & Tubing head spool) C- The 'Christmas tree.’
- 11. A- Casing Head A casing head is a simple metal flange welded or screwed onto the top of the conductor pipe. The casing head also serves to support the entire length of casing that is run all the way down the well. This piece of equipment typically contains a gripping mechanism that ensures a tight seal between the head and the casing itself. Casing Head Spool : used in flanged wellhead assemblies to secure the upper end of a casing string and to suspend and seal the casing. Casing Hangers: is that portion of a well head assembly which provides support for the casing string when it is lowered into the wellbore. When the casing string has been run into the wellbore it is hung off, or suspended, by a casing hanger, which rests on a landing shoulder inside the casing spool. Casing hangers must be designed to take the full weight of the casing, and provide a seal between the casing hanger and the spool. CSG hanger CSG head spool
- 12. B- Tubing Head A spool-type unit or housing attached to the top flange on the uppermost oil-well-casing head to support the tubing string and to seal the annulus between the tubing string and the production casing string. Tubing head is a wellhead component that supports the tubing hanger and provides a means of attaching the Christmas tree to the wellhead. Tubing Head Spool: Piece of equipment attached to the uppermost casing head or smallest casing string which serves to suspend the tubing and to seal the annular space between the tubing and casing. Tubing hanger: is a device attached to the topmost tubing joint in the wellhead to support the tubing string. The tubing hanger typically is located in the tubing head, with both components incorporating a sealing system to ensure that the tubing conduit and annulus are hydraulically isolated. TBG head spool TBG hanger
- 13. Safety Control Sub-Surface Safety Valve A Safety Control Sub-Surface Safety Valve (SCSSV) is a down hole safety device installed in a well which can be closed in emergency. An emergency may arise on or around a well from equipment failure, human error, fire, leaks. The reason for using an SSSV is to provide protection to site and off-site personnel, surface facilities the environment and the reservoir. These valves are commonly uni-directional flapper valves which open downwards such that the flow of wellbore fluids tries to push it shut, while pressure from the surface pushes it open; This means that when closed, it will isolate the reservoir fluids from the surface. Most down hole safety valves are controlled hydraulically from the surface, meaning they are opened using a hydraulic connection linked directly to a well control panel. When hydraulic pressure is applied down a control line, the hydraulic pressure forces a sleeve within the valve to slide downwards; This movement compresses a large spring and pushes the flapper downwards to open the valve. When hydraulic pressure is removed, the spring pushes the sleeve back up and causes the flapper to shut. In this way, it is will isolate the wellbore in the event of a loss of the wellhead.
- 14. C- Christ-mass Tree: A Christmas tree (X-mas tree) is an assembly of valves and fittings which forms the top of the completion. It is connected to the tubing hanger spool and directs the flow of fluids from the production tubing into the production flow line. It also provides vertical access to the production tubing for well servicing and side access to the production tubing for pumping services, i.e. well kill, circulation and chemical injection facility. The type of the X-tree may vary according to the reservoir pressure ( We have 5K, 10K, & 15K).
- 15. C- Christ-mass Tree: Christ-mass Tree Valves: 1- Upper Maser Valve (UMV): Is used on moderate to high pressure wells as an emergency shut-in system. 2- Lower Maser Valve (LMV): Utilized on all Christmas trees for contingency to the UMV to shut off well flow in the event of a leaking UMV or the connection between them. 3- Flowing Wing Valve (FWV): The FWV permits the passage of well fluids to the choke. 4- Choke Valve: To restrict, control or regulate the flow of hydrocarbons from the well. 5- Killing Wing Valve: Is used for equalization and permits entry of kill fluid into the completion string. 6- Swab Valve: Permits vertical entry into the well for well servicing Activities. 7- Surface Safety Valve (SSV): Is a hydraulically actuated gate valve for producing oil & gas wells can be installed as a part of the X-tree or at the flow line; used to quickly shut down the well upstream in the event of overpressure, failure, a leak in downstream equipment, or any other well emergency requiring an immediate shut down.
- 16. Types of Christ-mass Tree: FMC X-tree Wood Group Cameron Aker
- 17. Hook-up & Flow Line Is a pipe conform the dimensional requirements of ASME (American Society Of Mechanical Engineers) and used for conveying Liquid, Gas or any thing that flows. The selection of a flow line depends on the Flowing and the shut-in pressure-temperature, and the flow rate. The size of the flow line may vary from 1 inches to 24 inches with various Schedules (ex. 40, 80, 160) including Valves and Flanges with various classes ( ex. 150, 300, 600, 900, 1500, 2500) and .
- 18. Flow Line Different Sizes & Schedules
- 19. Flow Line Different Sizes & Schedules
- 20. Max. Allowable PressurePressure Class 425 psi150 1100 psi300 2175 psi600 3250 psi900 5400 psi1500 6600 psi2500 Valves & Flanges Pressure Classes
- 21. Flow line Material The most common flow line material is carbon steel and Stainless steel. Stainless steel differs from carbon steel by the amount of chromium present. Unprotected carbon steel rusts readily when exposed to air and moisture; This iron oxide film (the rust) is active and accelerates corrosion by forming more iron oxide. Stainless steels contain sufficient chromium to form a passive film of chromium oxide, which prevents further surface corrosion by blocking oxygen diffusion to the steel surface and blocks corrosion from spreading into the metal's internal structure; the most preferable type of stainless steel is the Duplex and specially at gas wells.
- 22. Flow line Material ( Carbon Steel ) Carbon steel is the most common pipe material in hydrocarbon industries. Carbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.12– 2.0%; As the carbon percentage content rises, steel has the ability to become harder and stronger through heat treating. Steel pipe is generally used for pressure piping. The advantages include long laying lengths, high internal and external strength and the availability of varying pipe thickness to meet almost any design pressure. The most serious disadvantage is its low resistance to corrosion which makes it a requirement for internal and external protection, with galvanizing the most commonly used method.
- 23. Flow line Material ( Duplex Stainless Steel) Duplex steel combines the advantages of ferritic and austenitic steel. It has excellent resistance to the various corrosive media that are typically found in both onshore and offshore environments. These mainly include CO2, H2S gases, chlorides, low ph conditions, and water. Its high strength is extremely beneficial in dealing with the high pressures. ferritic Duplex
- 24. Flow Line Fittings Flow Line fitting main objectives:- 1. Produce change in geometry 2. Modify flow direction 3. Bring pipes together 4. Alter pipe diameter
- 25. Flow Line Fittings The most common types of Flow line Fitting are as follow: 1. Elbow : It is a pipe fitting installed between two lengths of pipe or tube allowing a change of direction, usually 90° or 45°. 2. Tee-Connection : is used to either combine or split a fluid flow. Most common are tees with the same inlet and outlet sizes.
- 26. Flow Line Fittings (Cont.) 3. Reducer : is used to Change the piping diameter. 4. Gasket : is soft material used to be inserted between two flanges. 5. Expansion Joints : are used in piping system to absorb thermal expansion.
- 27. Flow Line Flanges Types of flanges Loose flange :- Are classified as 1. Thread flange: Threaded Flanges are used for special circumstances with their main advantage being that they can be attached to the pipe without welding. 2. Slip on flange: Slip-On Flanges are probably the most common type of flanges in the industry and ideal for lower pressure applications. 3. Blind Flanges : This flange is used to seal the end of pipes systems and prevent flow, making it easy to conduct pressure tests.
- 28. Flow Line Flanges (Cont.) Integral flanges :- It is casted with integrally nozzle neck as:- 1. Socket weld flange : Socket Weld Flanges are similar to slip-on flanges, however, socket welds have an internal recess on the inside diameter to allow for a smoother flow of the process fluid. 2. Weld neck flange : Weld Neck Flanges have a long tapered hub it is important to specify the schedule pipe is being used for. This is because the inside diameter of the flange will match the inside diameter of your pipe
- 29. Flow Line Flanges (Cont.) Types of Flange Faces : 1. Raised Face (RF) : is the most common type used in process plant applications, and is easily to identify; It is referred to as a raised face because the gasket surfaces are raised above the bolting circle face. 2. Ring-Type Joint (RTJ) : The Ring Type Joint flanges are typically used in high pressure; They have grooves cut into their faces which steel ring gaskets.
- 30. Flow Line Valves The types of most common used Flow line Valves are as follow : 1. Ball Valve : is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball to control flow through it. It is open when the ball's hole is in line with the flow and closed when it is pivoted 90-degrees by the valve handle. 2. Gate Valve : is a valve that opens by lifting a round or rectangular gate out of the path of the fluid; Gate valves are primarily used to permit or prevent the flow of liquids, but typical gate valves shouldn't be used for regulating flow.
- 31. Flow Line Valves (Cont.) 3. Globe Valve : is a type of valve used for regulating flow in a pipeline, consisting of a movable disk- type element and a stationary ring seat in a generally spherical body. 4. Butterfly Valve : is a valve which can be used for isolating or regulating flow. The closing mechanism takes the form of a disk. Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they are lower in cost to other valve designs as well as being lighter in weight
- 32. Flow Line Valves (Cont.) 5. Check Valve : non-return valve or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. 6. Choke Valve : is a type of control valves, mostly used in oil and gas production wells to control the flow of well fluids being produced; the main advantage of choke valves is that they can be designed to be totally linear in their flow rate.
- 33. Flow Coefficient (Cv ) : The flow coefficient of a valve is a relative measure of its efficiency at allowing fluid flow. It describes the relationship between the pressure drop across the valve and the corresponding flow rate. The use of the flow coefficient offers a standard method of comparing valve capacities and sizing valves for specific applications that is widely accepted by industry. Mathematically the flow coefficient can be expressed as: where: Cv = Flow coefficient or flow capacity rating of valve. F = Rate of flow (US gallons per minute). SG = Specific gravity of fluid (Water = 1). ΔP = Pressure drop across valve (psi).
- 34. Installation & Testing Installation of the flow line go through the following steps: 1. Fabricating the Hook-up. 2. Stringing the Hook-up and the Flow line sections from the well head to the station manifold. 3. Welding activities. 4. Radiography activities. 5. Hydro testing 6. Tie-in the Hook-up to the well head and the flow line to the manifold.
- 35. Gas Well Hook-up Components
- 36. Hook-up Components 1. X-mass tree 2. Pressure & Temperature transmitters 3. HIPPS 4. choke valve 5. Pilots 6. Venturi Device 7. Transmitter Panel 8. Testing Package T-connections & Double Isolation. 9. Mono-Block Isolation Joint 10. Solar panel system 11. Panels (RTU, flow computer, WHCP, Phone Cabins). 12. Remote Operating Control
- 38. Pressure & Temperature transmitters & Gauges 1. Well (Tubing Head) Pressure Transmitter & Gauge. 2. Flow Line Pressure Transmitter & Gauge. 3. Flow Line Temperature Transmitter & Gauge.
- 39. HIPPS (High integrity pipeline protection system ) Function of HIPPS Valve is to protect the wellhead , Flow lines , Headers and gathering system pipe works against over pressure. The HIPPS Valve has been located upstream the well head chock valve to avoid the risk that fragments from the choke could cause damage of the valve was located down stream the choke. It is hydraulically operated from the well head control panel.
- 40. choke valve Can be adjusted locally or remotely via hydraulic drive from the well head control panel and has a facility via fiber optic cable for automatic control of the gas process inlet pressure and train process shutdown. The function of the choke valve is to control the fluid flow from the each well according to the selected type of controlling, for choke control of each well , the operator can select via the DCS (Distributed Control System).
- 41. Pilots (Pressure Switches) A pressure switch is a form of switch that closes an electrical contact when a certain set pressure has been reached on its input. The switch may be designed to make contact either on pressure rise or on pressure fall. The Pressure limits are determined according to the Shut-in pressure of the well and the flowing pressure. There are Three Pilots : 1- Hi-Hi Pilot 2- Hi-Pilot 3- Low Pilot
- 42. Venturi Device The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe. As fluid flows through a venturi, the expansion and compression of the fluids cause the pressure inside the venturi to change. An equation for the drop in pressure due to the Venturi effect may be derived from a combination of Bernoulli's principle and the continuity equation. A venturi can be used to measure the volumetric flow rate (Q) :
- 44. Testing Package T-connections & Double Isolation.
- 45. Mono-Block Isolation Joint Cathodic Protection (CP) is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects the metal to be protected to a more easily corroded "sacrificial metal" to act as the anode. The sacrificial metal then corrodes instead of the protected metal In pipelines carrying fluids with a separate water phase, there is a risk of internal corrosion caused by electric current leaving the internal surface of the pipe close to the isolating joint on the side that has a less negative internal potential (anodic side). This is mainly dependent on the conductivity of the fluid and the voltage between both sides of the isolating joint.
- 47. Panels WHCP : Well Head Control RTU : Remote Terminal Unit
- 48. Panels Flow Computer Phone Cabin
- 49. Remote Operating Control Each well head site has a remote telemetry unit that communicates via the fiber optic link to the main control room (DCS).