21/7/2018
Golf station visit (G) :
Well design:
· Surface casing which is the first part under the charismas tree, it is mostly 16 in diameter. Under that the intermediate casing followed by the production casing.
· The production casing covers the tube or the rod that’s moves up and down.
· Down in the reservoir there is the casing perforation which takes fingers shape. It is basically small paths for oil to come through.
Charismas tree:
· A Christmas tree is an assembly of valves along with adapters. It is usually the part that can be seen in the top of the well.
· Charismas tree is very beneficial to prevent any blockage, control the injection, and control system to the downhole safety valve.
· The two master valves (upper and lower), they lie in the flow path, which well fluids must take to get to the surface.
· The lower master valve will normally be manually operated, while the upper master valve is often hydraulically controlled.
· The left hand valve is often called the kill wing valve. It is primarily used for injection of fluids such as corrosion inhibitors or methanol to prevent hydrate formation.
· The right hand valve is often called the flow wing valve or the production wing valve; because it is in the flow path the hydrocarbons take to production facilities.
· The valve at the top is called the swab valve and lies in the path used for well interventions like wireline and coiled tubing.
Beam pump:
· The beam pump convert the rotation motion to horizontal motion in order to suck up the oil form the reservoir.
· Counterbalance weight is mainly for balancing two sides.
· Brake lever’s purpose is to stop the pump from operation manually.
· Polished rod’s diameter is bigger than the sucker rod, so it can afford the heavy lifting.
· The beam pump is operated by motor in the back side of it.
· When the upstroke raises the horsehead and the plunger, the oil is being pumped.
· The traveling valve is very important where it control the flow of the oil inside the plunger along with the standing valve. Those valves are being control by the fluid flow only.
· During the upstroke, the traveling valve is close while the standing valve is open. This situation allows the fluid above and within the plunger to be lifted up and no fluid is leaving the plunger.
· During the down stroke, the traveling valve is open while the standing valve is closed. This situation allows the fluid to go into the plunger and not leaving the well because the standing valve is closed.
Multi selector valve (MSV):
· The MSV is a highly efficient fluid controller system. It is the first stop for the oil that is coming from the well where one MSV collect the oil from 7 different wells.
· Inside the MSV there is a selector device that reroute the fluid to a testing path in order to do some testing for the fluid in another location such as the lab.
· There is a production outlet next to the test outlet which is for the fluid that doesn’t need any testing and its leads to the manifold.
· In case of no testing is needed, the selector turn to the 8th port where no oil is passing through it.
Manifold:
· It is basically a pip that takes the oil from the MSV to another station. Normally it has several lateral outlets.
· It is mainly to distribute and monitor the flow rate.
|attending a pigging launch :
In-field experience:
· The permit holder starts with the tool box meeting and specified the hazardous and how to prevent ourselves form them along with the whole procedures.
· The workers start with checking the valves such as the by-pass valve (A) is open.
· They closed kicker valves C1, C2, C3, and main isolation valve B.
· Confirm that the drain valves D1/D2 and balance valve (I) are closed and the pressure is zero along with the door (F) is closed and secured.
· Check the vent valves E1/E2 are closed and the drain pits and door pit are empty.
· After that, they opened door (F) and loaded the pig into the barrel and pushed the pig about 8 meters inside the barrel.
· They opened (I) valve in order to prevent any contact of pig with B valve.
· They opened C2 and C3 valves to balance the pressure inside the barrel.
· Close E1, E2 after the barrel has been felled up with oil to pressurized.
· Check the P-gauges and ensure that they have some reading of the line.
· Open C1 and closes C2, C3, and I
· Reset G1 and G2 pig signal.
24/7/2018
Thuleilat gathering station visit (THL):
Thuleilat is a sour area and it is basically a gathering station. The fluid comes from three different places which are Rahab, Qaharir and Thuleilat itself. It is also water injection facility. Once the fluid comes to the station, it goes to free water knock out tanks (FWKO) where they have two tanks. Due to the water have higher density than the oil, it will go down and the oil will go up inside the tank. Thus, they use the settling tactic to separate the fluid. After that, by using transfer pumps; the fluid goes to the (GFT) separator for further separation by using micro bubble method. Next, the oil is being shipped to the Marmul main production station (MMPS) and the water goes to the injection wells. In Thuleilat, they do one type of testing which called basic sediment in water (BS&W) which is to check the percentage of water in oil by using some chemical called F46. They have two types of pumps which are positive displacement pump (PDP) and centrifugal pump. Centrifugal pump has a large discharge and small heads where PDP has small discharge and higher head. Furthermore, centrifugal pump can lift fluid with high viscosity such as oils, paper pulp, and chemicals. In the other hand PDP can only handle pure water and very low viscosity fluid. Centrifugal pump can be used for uniform and continuous flow and PDP for fluctuating and pulsating. Also, centrifugal pump can operate on higher speed and hence coupled with motor where PDP can operate on low speed and hence gear driven.
Water treatment plant visit (WTP):
Water treatment plant is an advance station for water treatment. The dirty water come from Marmul main production station (MMPS) directly to the primary treatment in the (WTP). The mechanism that been used in the primary treatment called induced gas flotation (IGF). (IGF) is a hydraulic flotation technology that has been used to reduce the solid and oil in water fraction. There are 6 primary treatment columns and only 5 of them operate in normal daily bases and one of them is stand-by column. Primary treatment tanks can operate on pressure of 100 kPa and volume of 54 m^3. The water goes though eductor in order to add gas to the water stream. Next, the water goes to the disperser for formulation of micro size bubbles. After that, the fluid goes to the coalescer for oil and solid flocculation.
After the primary treatment, some of the water go to water storage tank and by using booster pump the water will be send to PDO wells for deep water disposal (DWD). Also, some of the water will go to the secondary treatment for more separation. In the second treatment, the technique that been used is called Filtration by Nutshell Filters which is Hydronation Deep Bed Filter (HDBF). The purpose of it is to reduce solid and oil in the water fraction. The main characteristic of the second treatment vessel is that the pressure is at 100 kPa and the capacity is at 86 m^3. There are 3 units in the station; only 2 works in the normal daily bases and 1 is a stand- by for any unordinary circumstances. From the second treatment, the water goes to Marmul Polymer plant (MPP) for polymer preparation and for polymer injection.
Attending continuous improvement session (CI):
CI is a way of recognizing chances of developing any job and reducing waste. This act was formalized by the popularity of Lean. Lean is basically having a mind set of being creative in the workplace in developing ideas to make the job easy, beneficial, and more practical without (
Identify
)reducing the quality of the job.
(
The continuous
improvement cycle
)
(
Plan
)
(
review
)
(
execute
)
First of all, we should identify the issue and then plan and organize the possible solutions and then start applying the solution and then check the benefits of the changes and affects.
Alpha gathering station visit (A):
A-station is basically a gathering station for the fluid. The fluid comes directly and only from production wells. The station have gathering manifolds, (MSVs), separations vessel, oil surge tanks, and shipping pump. It also have test/bulk de-sander units which is the only thing that makes this station different from other station. The fluid comes form the very sandy wells for treatment in this station. For the test de-sander case, the fluid come from the wells to the MSVs and then goes to the de-sander units and then goes to the multi-phase flow meter (MFM) and then goes to the separator units. likewise, the bulk header case is the same as the test de-sander except the fluid doesn’t goes to the (MFM) Hydro-cyclone de-sander unit operates in continuous mood and at low flow rates. The pressure drop considerably across the hydro-cyclone causes a reduction in the separation efficiency. Maintaining a minimum pressure is necessary across the hydro-cyclone where it is possible by manipulating the water supply valve. A fluid with high amount of sand will be send to a place called vent which is basically a place for the useless fluid. Later on, the fluid will be transfer to somewhere else by trunk. After the separator the fluid goes to the storage tanks and then it will be sent to the MMPS.
Preparing the separator for maintence:
Shutdown procedures:
1. Shutdown the separator unit by closing the inlet valve, so that the fluid level will not increase.
2. Opining the outlet valve line will help to reduce and empty the separator.
· The fluid can be sent to the storage tank by the outlet line up to the LL level.
3. Reduce the pressure by opining the gas outlet line up to certain pressure to help draining the oil and avoid vacuum
4. After the level reach the LL level the outlet (emergency shout down) valve ESD will closes, so no outlet line will be closed, therefor, the drain line will be opened to continuous removing oil form separator.
5. Depressurizing the separator to the flare and remove all gases.
6. Close the drain line.
7. Open the vent line which is 2” vent line foe gas discharge.
8. Drain the remaining oil to the open drain and transfer the oil from the pit by vacuum tanker.
9. Flash the separator by water to clean up the separator.
10. Purge the separator with N2 gas.
11. Open the separator to the atmosphere.
12. Purge the separator with air and create a healthy atmosphere for the workers.
13. Open all holes in the separator to let the air cycle from one hole to another.
14. Test the atmosphere inside the separator.
15. Prepare confined space entry certificate.
16. Clean the separator with high pressure water to remove any slugs or sand.
In case of restarting the separator again after the maintence is done, we should obtain a permit called statement of fitness which must be signed by a supervisor. The supervisor must carefully check all the equipment such as, valves and lines before giving the green line for it to restart.
Trip level and alarm management:
In all station, there are many alarms that happened normally when something is wrong with any unit. High high (HH) level alarm will case trip to the unit. The reaction will be closing the outlet valve for the unit because the level is high and more than the normal level. Vis versa, the inlet valve will close in case of Low low level (LL) because the level is too low in the unit which will lead to increase the level in the unit. In case of High level (H) it will only show an alarm in the station computer and that will be happened only if the level is high in the unit but did not reach the maximum level. In case of low level (L) it will only show an alarm in the station computer and that will be happened only if the level is low in the unit but did not reach the minimum level. The alarm should be managed by the operator otherwise it will cause a trip. In case of unit trip, the valve that been close automatically should be reopen by operator otherwise it will case the other type of trip. For instance, if (LL) trip happen that will close the inlet valve and if no action was taken, then the level will increase and will cause (HH) level trip.
Marmul polymer plant visit (MPP):
The principle of Polymer flooding is to displace the heavy oil and improve the reservoir sweep efficiency by flooding it with high viscosity water. Polymer Flooding reduces the mobility difference between water and oil resulting in more stable and piston like displacement with increased oil recovery. This station need three main facilities which are a produced water treatment plant (WTP), polymer solution preparation plant, and polymer injection facility. Polymer injection is more beneficial than water injection because it polymer has high viscosity than water.
Polymer injection water injection
The station procedures:
1) First the tanker is weighted by truck scale to measure the gross weight, as shown in picture 1.
2) Then, the unloading process of chemicals such as thiourea and polymer are then taking place and earth cable is connected from the tanker to the ground in order to remove any electrostatic charges.
3) After the unloading process is completed, then the tanker is weighted by truck scale to measure the tare weight to find out the total net weight.
4) The polymer is fed into the transfer vessel (2 transfer vessels) which will be working simultaneously. Then, it will be transfer into silo vessel (4 silo vessels) working as storage tank. The repartition vessel receives polymer from silo by gravity removing the air by injecting the nitrogen. The two transfer vessels are used to transfer the polymer into the slicing units (5 slicing units).
5) The polymer slicing unit consists of polymer hopper, conveying screw and slicing unit. Polymer hopper is used to receive powder from the transfer powder vessel and then goes to slicing unit through the screw conveyer.
6) The slicing unit is used to reduce the polymer particle size by screw conveyer. Then, it goes into the mixer in which the water and the polymer powder are mixed in 1:7 ratio.
7) The suction line that coming from the mixer will be pumped through mixer pump into maturation tank.
8) The maturation tank (2 maturation tanks) receives the polymer mother solution and it included of 4 chambers, for each chamber has an agitation to mix the solution properly. Also, after filling the first chamber the solution will overflow into the next chamber and gradually into the last chamber.
9) The stabilized mother solution will be pumped through 46 polymer injection pumps to injection wells.