Constructing a New Strategic Oil Storage Tank 30-10-2022
Within the strategic planning and developmental approach to meet the company's technical needs towards improving production and export operations,
SAFER decided to build two new crude oil storage tanks beside the two existing tanks at the central production unit – CPU. The new tanks shall have the same capacity, dimensions, and engineering as the existing Main Crude Oil Tanks,
considering the latest API 650 code. However, due to the high cost of building storage tanks and for the time being, SEPOC has started constructing only ONE of these tanks with a capacity of 55000 barrels
. The civil work has been almost completed and the mechanical work is ongoing.
Crude oil tanks are storage units used to store untreated/ unrefined oil to transport it to other locations like the refinery unit for processing into finished products or to the export station. A typical fixed-roof tank consists of a cylindrical steel shell with a cone- or dome-shaped roof that is permanently affixed to the tank shell. Storage tanks are usually fully welded and designed for both liquid and vapor-tight.
Based on its location within the system and its type of configuration this tank will serve either for providing crude oil storage volume i.e., tanks utilized as a logistical midstream link between exploration and production (the upstream) and the refining facility (downstream), or for gasoline storage that comes from the Marib Refinery.
For high safety measures, storage tanks must be professionally engineered to provide proper protection — via alarms and high-high level interlocks — against overfilling of hazardous materials and the resulting spillage. This tank, therefore, is fully supervised by the SEPOC engineering team giving it full attention and consideration. Both the safety and engineering departments bear in mind that it is decisively critical to maintaining the integrity of tank venting systems. Otherwise, catastrophic damage may result.
Block-18 Production Facilities
Oil is processed through two main facilities in the Marib area; these facilities are the Central Production Unit (CPU) and the Kamil Production Unit (KPU).
Al Raja, Al Shura, and Raydan are three smaller facilities connected to the CPU and KPU facilities; SEPOC receives crude oil from JHOC, OMV, and Calvalley for processing and export through our pipeline.
SEPOC also supplies Marib Refinery Company with 10,000 bbls per day.
CPU is the collection point for all SEPOC facilities. There are three gas plants, two cryogenic, and one lean oil plant capable of processing crude oil through vessels arranged according to pressures: from over 1000 psi to 1 atm.
As the oil from each vessel is metered to a lower pressure, separated gas goes to headers and is transferred to the gas plants or is compressed for injection; water collects and is pumped to special disposal wells.
This process separates oil, gas, and water, and removes all salts and sediments from the oil.
There is also a freshwater injection system that injects fresh water into wells and pipelines for sediment removal.
CPU is the main gathering process facility for Block-18 Fields, 416 wells are connected to the CPU process facility through production and injection flow lines with many production manifolds
16 fields (Alif, Azal, Wadi Bana, Jabal Barat, Jabal Sama, Jabal Samadan, EL-Wehada Noqum, Wadi Saba, Shura, Yazen, and Mawza, etc..) are flowing to the 6 process trains A, B, C, D, E and F trains.
CPU process facility includes five main production manifolds, these manifolds are North Manifold (NM), South Manifold(SM), Old Expansion Manifold (OEM), New Expansion Manifold (NEM), New Expansion Sapar
SEPOC Fields Production
KPU consists of a production train (test separator and 7 high-pressure vessels), water disposal pumps, and a freshwater system. KPU is the collection station for Al-Raja and other small, remote fields.
Al-Raja is a high-pressure facility (more than 5,000 psi). It includes a manifold, testing vessels, and separators. The facility also includes one compressor.
Raydan is a low-pressure facility (less than 1000 psi). It includes several vessels of different pressures and 9 Ajax compressors for gas injection. Raydan also has several water pumps for disposal and several crude transfer pumps for sending oil to the CPU. ator System, Low-Pressure Manifold.
Kamil Production Unit (KPU)
KPU consists of a production train (test separator and 7 high-pressure vessels), water disposal pumps, and a freshwater system. There are also two cryogenic gas plants and four Nuovo Pignone compressors for gas handling. KPU is the collection station for Al-Raja and other small, remote fields. There is a complete accommodation setup including recreation and sporting facilities
Al-Raja is a high-pressure facility (more than 5,000 psi). It includes a manifold, testing vessels, and separators. The facility also includes two compressors: the first, a Nuovo Pignone, and the second, a Cooper Rolls Royce. Al-Raja has a complete personnel accommodation setup.
Raydan is a low-pressure facility (less than 1000 psi).
It includes several vessels of different pressures and 9 Ajax compressors for gas injection.
Raydan also has several water pumps for disposal and several crude transfer pumps for sending oil to the CPU. Finally, the facility includes a 15,000 bbls storage tank and a 5000 bbls water tank.
Raydan has a complete personnel accommodation setup.
Al-Shura utilizes 6 Ajax compressors, several separators of low and high pressures, and a freshwater injection system.
The Field Operations department is divided to 3 main sub-departments: 1.
Production Department The production department consists of three main areas:
A. Field Operations: Field operations take care of all active wells (producing, disposal, injection, and water wells). All wells (more than 600) are monitored two to three times a day.
It also cleans wells and flow lines through pump trucks and coiled tubing units. The Field Operation sections are controlled at the CPU and KPU. All other fields are operated through these units, depending on distance.
B. Facility Operations Facility operations handle all crude separation processes that separate oil, gas, and water. It also operates the utility and power generation areas.
C. Workover Group: The workover group is responsible for well workover and completion after drilling.
It consists of an engineering group at the CPU that monitors all drilling rigs.
Their scope is to remedy mechanical problems with the wells such as leaking packers, casings, and tubings.
The workover group also repairs the formation of the well if becomes non-productive or reduced in efficiency.
These three Field Operation sub-departments are managed by production superintendent.
The superintendent directs field supervisors, production foremen, and shift supervisors.
The superintendent also manages rigs through the senior production engineer.
Workover Operations - Challenges and Achievements 19-10-2022
The question that poses itself" How could SEPOC workover activities continue during war conditions and in the absence of well cementing and other well services companies during the current company and country situation?”
The brief answer to this question is one-word "innovation"
In actual fact, these challenges did not only represent a hindrance to the workover team as much as they were an opportunity for this team to ingeniously create new ideas and creative solutions that would not have seen the light without those exceptionally difficult circumstances. This corresponds to the saying “Necessity is the mother of invention”
These creative solutions, which have started to flow continually since resuming the workover rig operations in mid-May 2018, have resulted in the continuation of regular workover activities and further improved the quality, efficiency, and kind of these operations.
Due to the absence of new wells drilling operations, the philosophy of SEPOC workover operations has changed to be based on the principle of (No Replacement for any well). Consequently, any well must be repaired by any possible safe procedure. This in turn led to the invention of new workover practices that had never been practiced in the SEPOC field before.
Below we may include some of these creative solutions as good experienced examples: -
- Building cement mixing and pumping equipment using the available company materials and equipment. Developing cement mixing procedures and cement equipment performance to keep cement jobs progressing with good quality.
- Performed more than 60 successful cement jobs during the last 4 years including cement plugs and casing leak repair cement squeeze.
- Replacing the top bad portion of production casing by casing back off without prima cord explosion. Every well has its unique challenges and problems.
- Using new low-cost and reliable drillable bridge plugs, cement retainers, and hydraulic set permanent packers manufactured by some Asian Companies
- Using the MHS packer as a mechanical barrier in place of a rental retrievable bridge plug (RBP) to secure wells to do the required work on the wellhead.
- Modifying Chamber Lift Mandrels (CLM) and Side Pocket Mandrels (SPM) for downhole freshwater injection systems repair.
- Inspecting, evaluating, and re-using the retrieved old tubing from the wells, either 3-1/2" API EUE tubing or 4-1/2" premium connection type saving the need for new tubing.
- Saving the permeant type packers (like Halliburton VSR or WB packers) in place in many gases’ injection or gas producer wells, by using work string with many modified fishing tools thru casing or thru tubing to retrieve stuck mechanical plug and prong in packer tailpipe.
- Replacing the bad top part of the surface casing by digging around the well to depths reached 60 ft below ground level.
- Mixing Water Based Mud (WBM), a new type of Loss Circulation Materials (LCM) & casing packs Oil Base Mud (OBM).
- performed several rig repairs using spare parts from the junkyard.