During the past five years, ADNOC Exploration and Production (E&P) sector successfully continued its rigorous and environmentally conscious endeavours to optimize hydrocarbon recovery, reservoir management and upgrade exploration opportunities utilizing leading edge technologies. This has been carried out through facilities and infrastructure enhancement projects, expedite progress on gas reservoirs appraisal and development projects and extensive seismic and subsurface data gathering, processing and interpretation for both exploration and development purposes.
Several marine, transitional zone and land exploration and development 3D seismic surveys were acquired in Abu Dhabi in the last five years using state-of-the-art geometry designs, equipment and geophysical technologies. The acquisition was followed by high resolution 3D seismic data processing to optimize the data quality for exploration prospect mapping, reservoir characterization and drilling decisions in existing oil and gas reservoirs.
A large land vibroseis high resolution 400 fold 3D seismic survey was acquired over an onshore gas reservoir for appraisal and field development planning and was completed three months ahead of the contractual time, excellent HSE results with zero Lost-Time-Incident (LTI), complete coverage of the full fold area and under budget due to high quality performance by all parties involved while strictly adhering to ADNOC technical and HSE specifications and policies.
Another exploration 3D seismic survey was acquired successfully in transitional zones environment using dynamite and vibroseis on land, shallow marine sources and receivers and ocean bottom cable in deeper waters.
Additionally several oil field development 3D seismic surreys have been acquired and/or reprocessed to generate high resolution volumes that can be used in mapping small faults, porosity distribution and large fracture clusters in multiple shallow and deep oil reservoirs.
The E&P sector is also currently conducting several research and development (R&D) projects and pilots to test the applicability of several advanced and new technologies in the areas of multi-components, time-lapse 4D, single source and single sensor and 3D VSP. Results of these trials can have significant impact on future deep gas exploration and development projects.
National Drilling Company (NDC) is one of the largest drilling contractors in the Middle East, and has over 30 years’ experience in the industry. The Company’s modern fleet now totals 10 offshore rigs, and 16 onshore drilling and work-over rigs. There are also six water well rigs operating in the Ground Water Research Project, where NDC is working with the US Geological Survey on two studies to evaluate the ground water resources of Abu Dhabi and Al Ain. Fleet downtime for NDC ranks as one of the best in the drilling industry, with an average of 99.5 percent uptime, providing customers with an efficient, round-the-clock service. The Company also has an impressive safety record. For example two onshore rigs, ND-1 and ND-8, completed more than five calendar years without a Lost Time Incident in 2001.
In 2003, NDC launched the first in a new generation of state-of-the-art land drilling rigs. Embracing cutting-edge drilling technology for higher performance and lower downtime, ND-31 is capable of drilling to a depth of 20,000 feet with a 5 7/8 inch drill pipe. It is custom-designed to drill clustered wells on a 3 x 8 pad (three rows, each with eight wells), with 15 to 20 feet spacing and 30 to 40-row spacing, delivering higher well capability and flexibility.
The Company invested heavily to ensure compliance with Group health, safety and environmental (HSE) requirements. The environmentally friendly design ensures zero discharge, and uses extensive mechanization to improve working conditions and keep staff away from high-risk areas. The whole rig remains stationary except for the substructure and mast, which can be moved over a cluster of wells.
ADNOC’s oil and gas fields were developed extensively between 2000 and 2007. Major oil development programs were implemented mainly in the existing producing fields to expand production facilities and achieve the target of the 25-year plateau production rates. Optimising the progress within the existing fields maintained the production rate and helped to derive cost advantages by improving the use of existing facilities and infrastructure. Significant achievements were made in expanding gas development fields to meet increased demand from industry gas users and gas injection requirements in order to enhance oil and condensate recovery.
Between 2000 and 2007, development drilling activities continued at a peak level, both in the onshore and offshore areas, and concentrated mainly on the drilling of development wells in major oil and gas producing fields. A total of 8.6 million feet were drilled during this period. Improvements in drilling performance were vigorously sought for most types of wells, with major achievements recorded in horizontal drilling operations.
During the last five years, nearly 1,000 wells have been drilled and worked over in onshore and offshore fields. The introduction of DTL in drilling and work over operations has improved efficiency and reduced cost by 35 percent and 25 percent, respectively.
Developments – Onshore
Major onshore oil developments during this five year period include the North East Bab Phase 1 (NEB-1) project, designed to increase production from Al Dhabb’iya, Rumaitha and Shanayel fields to 110 MBOPD by early 2006. This includes the implementation of the Water Alternating Gas (WAG) process for the first time in the Gulf area to obtain maximum production while sustaining the reservoir pressure. The latest Supervisory Control & Data Acquisition (SCADA) technology will also be utilised for this project. The oil and gas development comprises a central processing plant, clusters of wells and gas injection wells, a network of underground flow lines, transfer pipelines, and a new transfer line from NEB to Habshan. The supporting infrastructure facilities include an administration building, accommodation complex, recreation facilities, landscaping and roads, together with power transmission lines and a water supply pipeline.
New Enhanced methods for oil fields development offshore
Evaluation of new production enhancement methods using gas inj. are implemented over the last five years include Umm Shaif field crestal gas injection, Upper and Lower Zakum fields' pilot gas injection, Umm Al Anbar flared sour gas re-injection, and Bunduq associated gas injection projects.
New Gas Developments – Onshore
During this five-year period, major onshore gas development projects, designed to develop Abu Dhabi’s natural gas resources, were completed on schedule. These include Asab Gas Development (AGD) and Onshore Gas Development Phase-II (OGD-II).
Asab Gas Development (AGD)
project was completed and commissioned in April 2000. This project is designed to produce natural gas from the Asab field reservoirs and extract the condensate. The separated and dehydrated gas is recycled into the two gas producing reservoirs. AGD comprises drilling gas producers and gas injectors, gas pipelines and processing facilities for condensate recovery, and a compression station to recycle the dried gas. The produced condensate is pumped through a new pipeline to Ruwais refinery.
Onshore Gas Development Project Phase II (OGD-II)
was completed and commissioned in April 2001. This is designed to produce dry sweet gas and condensate from the three reservoirs at Bab field. OGD-II comprises drilling gas-producing wells from non-associated gas reservoirs, and the installation of a new plant within the existing OGD-I premises. This plant has facilities for gas processing and condensate stabilization. The dry sweet gas supplies ADNOC’s gas pipeline network, while the condensate is pumped to Ruwais refinery. There are also a number of key developments currently being implemented:
Asab Gas Development Project Phase II (AGD-II).
The Front-end Engineering Design (FEED) phase for AGD-II was launched in 2003. The objective is to continue the development of the facilities at AGD-I. AGDII will mainly involve recovery of NGL from the 743 MMSCFD of sour, rich gas that is presently processed at AGD-I, and injected into the wells in the Asab area.
Onshore Gas Development Project Phase III (OGD-III).
Following the successful commissioning of OGD-I in 1996 and OGD-II in 2002, the Front-end Engineering Design (FEED) phase for OGD-III was launched in 2003. Production at the proposed new gas plant, which will be located south of the existing Habshan complex, is forecast to start in 2008. The main objective is to generate additional revenues from increased production of both condensate and NGL. The feed gas for the new OGD-III plant will be sourced from Thamama F reservoir of the Bab field. The new plant will be designed for total capacity of over 1,300 MMSCFD of well-stream fluid, resulting in the supply of over 1,200 MMSCFD of gas to the treating section. Associated facilities include a gas gathering system, two condensate separation and stabilization trains, two gas treating trains, two NGL recovery trains, and four re-injection compression trains.
OGD-III and AGD-II
associated expansion projects.
The condensate produced by OGD-III will be routed to Takreer (Ruwais) for fractionation and export. The existing condensate storage facilities at the refinery will be expanded. Likewise, the NGL from both OGD-III and AGD-II will be routed to GASCO (Ruwais) for treatment, fractionation and export. This plant will also be expanded and will be designed with capability to produce additional ethane as feedstock for the planned increase in polyethylene production by Borouge petrochemicals plant. The expected recovery of 4,800 tons per day of ethane will support a cracker of 1.4 MTPA capacities. A new pipeline system will be installed to transport NGL and condensate to Ruwais. After completion of the project, the gas processing capacity at the Habshan complex will increase to 4,500 MMSCFD, making it one of the largest gas complexes in the world.
Bab Thamama B Incremental Gas Cap Injection project consists of gas compression facilities to meet the additional sustainable gas injection requirement into Thamama gas cap, with completion due for late 2006.
New Gas Developments – Offshore
The ongoing Offshore Khuff Gas Development (OKGD) project involves the installation of new gas facilities to gather and export Abu Al-Bukhoosh Khuff gas to various applications via the Umm Shaif super complex. This will compensate ADGAS’s currently used GGII associated gas and help augment the gas supply to Umm Shaif Uweinat reservoir for pressure support, and the Lower Zakum crestal gas injection project to enhance oil production. Commissioned in December 2005.
Gas field development studies were completed in 2003 to evaluate the gas asset and production potential of two major reservoirs in the Khuff ABK and US fields. An additional preliminary study was completed in 2004 to develop the Mubarraz Arab gas condensate reservoir. In addition, a feasibility study for exporting offshore Khuff gas onshore for injection into Bab field (OGEP) is in progress.
During the past five years, continued emphasis was placed on sustaining the integrity of production facilities through improved maintenance and upgrading production and injection facilities. Particular importance was given to the long-term integrity of managing key production assets to identify and mitigate risks associated with the use of old equipment. Production operations for crude oil, water and gas injection, and gas supply were performed safely and efficiently to meet all targets, including increased export demand.
A number of major projects, designed to increase ADCO’s production capacity to 1.4 MMBPD by 2005-2006, are completed. These include expanding production facilities at Bab and Huwaila fields, and upgrading production facilities at Bu Hasa and Asab/Shah fields.
In 2003, ADCO awarded Snamprogetti the Engineering, Procurement and Construction (EPC) contract for the Bu Hasa Facilities Development Project at Bu Hasa Field, with total plant capacity of 730,000 BPD. The project consists of new centralized oil production facilities to handle increased GOR and water cut projected for the next 30 years. It also includes gas and water injection facilities, applying the water alternating gas (WAG) concept and variable speed motor drive for the injection compressor, with a capacity of 150 MMSCFD and 120,000 barrels of water per day. The project will utilize latest technology in Supervisory Control and Data Acquisition (SCADA), automation, and flare minimization to enhance operability and meet environmental guidelines.
Also in 2003, ADCO signed a contract with JGC Corporation of Japan for the construction of a new Central Degassing Station (CDS), as part of the Bab Expansion Project. This will comprise two trains, both including first and second stage separation, crude heating, hydrogen sulphide stripping, water separation, and associated utilities. An essential part of the plans to upgrade Bab’s treatment and production capacity, the new CDS is expected to be completed by the end of 2004.
In 2001, new effluent water disposal and oil dehydration facilities were commissioned on Zirku Island. Two major offshore projects were also introduced to upgrade gas injection facilities in Zakum and Umm Shaif fields. In 2000, the planned reorganisation of the Zakum site was implemented.
Abu Dhabi’s production of associated and nonassociated gas from the main fields has increased annually over the past five years to meet growing demand. Gas injection programmes for the pressure maintenance of oil and gas reservoirs continues. Gas supplies to the NGL plants at Asab, Bab, Bu- Hasa, Habshan and Ruwais, the LNG plant on Das Island, and the condensate plant at Ruwais, increased between 2000 and 2004. All gas supply requirements were fully satisfied with respect to power generation, water desalination and Abu Dhabi’s other industries.
In support of the Bab Oil Expansion Project, a conceptual study is underway to expand the crude oil production capacity of the Bab Crude Degassing Plant. The Habshan Gas Plant will be required to process 400 million SCFD of Thamama B associated gas. As part of the study, a capacity assessment of the plant’s feed gas processors and processing units is being carried out. The Umm Shaif-Habshan Gas Export project was commissioned at the end of 2003. As a result, the gas produced at Total ABK and Umm Shaif fields (540 million SCFD dry gas) is now utilised for injection into Thamama F and B zones. The project to supply an additional quantity of 270 million SCFD of gas to Taweelah A1 power and desalination plants was completed in 2002.
In 2002, a new E&P support services company – ESNAAD – was formed through the merger of Abu Dhabi Drilling Chemicals & Products Limited (ADDCAP) and National Marine Services Company (NMS). The new company, wholly owned by ADNOC, provides comprehensive and integrated support services to offshore oil and gas companies. Services include berthing, bunkering, bulk supplies, warehousing and waste disposal, augmented by a fleet of specialised marine vessels, including firefighting tugs. A grinding plant produces a range of mud chemicals including barite, bentonite and attapulgite, while a blending plant supplies drilling and production chemicals such as corrosion, scale and wax inhibitors, bactericides and de-emulsifiers. All materials conform to ISO and API standards.
Abu Dhabi Petroleum Ports Operating Company (ADDPOC), which was established in 1979, was renamed IRSHAD in 2002. The Company provides maintenance to offshore loading terminals, subsea equipment, and navigation aids. IRSHAD operates its own fleet of just under 40 vessels, including tugs, pilot boats, a dive support vessel, and a maintenance barge with a 20 ton hydraulic crane. In 2001, the Company was certified by the International Safety Management System (ISM Code).
Upstream ADNOC Group Companies: