Tamar Natural Gas Field, Israel
The Tamar field is a natural gas discovery made by Noble Energy in January 2009 and is the company's largest find to date.
Noble Energy owns 36% in Tamar and is the operator of the field. Isramco Negev 2 owns 28.75%, while two of Delek Group's subsidiaries - Delek Drilling and Avner Oil Exploration - own 15.625% each. The remaining 4% stake is held by Dor Gas Exploration.
According to estimates, the field has reserves of 10 trillion cubic feet (tcf) of gas. First production from Tamar was achieved in April 2013. The field reached full production capacity by the end of July 2013. The project was approved in August 2010.
Tamar gas field location
The Tamar field is located in the Levantine basin of the Eastern Mediterranean Sea. The prospect falls under the Matan licence, which Noble Energy has operated since July 2006.
The Matan deepwater block covers 318km² while the Tamar structure is spread over 250km².
The first appraisal well that discovered Tamar's natural gas reservoirs is 90km west of the port of Haifa on the Israeli coast.
Tamar natural gas discovery
The presence of natural gas in the Tamar field was discovered in January 2009. The discovery was made by the first appraisal well Tamar-1.
A total of three reservoirs were found by the appraisal well. Tamar-1 is located at a water depth of about 5,500ft. The well was drilled to a total depth of 16,076ft. The structure that the well tested is a lower-Miocene prospect.
A net pay exceeding 460ft was identified in the three reservoirs by the formation logs.
Tamar field reserves
Pre-drill estimates at Tamar were 3.1tcf of natural gas. Following flow testing of the first appraisal well in February 2009, the estimates were raised to 5tcf, then subsequently increased to 6.3tcf following the drilling of second appraisal well Tamar-2. As of 2013, reserves are estimated at 10tcf.
Further assessment of the discovery was carried out by an independent consulting firm Netherland, Sewell & Associates to confirm the resources at the field.
Tamar field development
The Tamar field is being explored because the 3D seismic data over the Levantine basin collected from Spectrum indicated potential for natural gas resources in Tamar and other fields in the basin. Development of the Tamar field started in 2003 when the first appraisal well was proposed to be drilled.
Named Tamar-1, the well targeted sands lying at 2,500m subsea. The cost of drilling the appraisal well was initially estimated at $40m, but escalated to more than $145m.
Tamar-1 discovered three high potential gas reservoirs at the field. During flow testing in the month that followed, Tamar-1 yielded a flow rate of 30 million cubic feet of natural gas per day (mmcf per day).
The expected production rate from the well was more than 150mmcf per day. The testing was conducted to a limited depth of 59ft.
In July 2009 Noble Energy completed drilling of the second appraisal well Tamar-2. The well is situated about 3.5 miles northeast of Tamar-1. Tamar-2 is at 5,530ft of water depth and was drilled to a total depth of 16,880ft.
Noble Energy collected additional 3D seismic data over 1,600 square miles of the Tamar region in the second half of 2009, after the drilling of Tamar-2 was completed. Based on the leads obtained from the seismic programme Noble Energy continued to explore the Tamar field before it started development drilling in September 2011.
The drilling of Tamar-2 confirmed high quality gas at the reservoirs and surged the total reserves at the field from 5tcf to 6.3tcf of natural gas. In April 2011, drilling of four more wells - Tamar-3, Tamar-4, Tamar-5 and Tamar-6 - began. Tamar-5 did not encounter any gas, but Tamar-3 discovered a new layer of gas at the field. This new discovery, layer D, was found at a depth of 5,160m and was expected to contain 0.5-1.5tcf of gas reserves.
Exploration is currently ongoing at the Tamar South-West prospect. The SW prospect was estimated to contain up to 705.3 billion cubic feet (bcf) of gas as of June 2013.
Atwood Hunter rig for Tamar gas field
The appraisal wells at Tamar were drilled by the Atwood Hunter rig, a semi-submersible rig owned by Atwood Oceanics. The rig can drill to a maximum water depth of 5,000ft.
Atwood Hunter was used to conduct drilling at Dalit, another Israeli field operated by Noble Energy.
Atwood Hunter was constructed in 1981 and refurbished in 1997. It was further upgraded in 2002 and can drill to depths of up to 28,000ft.
Gas is produced through five subsea wells tied back to the Tamar platform. The wells are linked to the platform through 150km long flowlines. The platform is installed at a depth of 800ft and has a processing capacity of 1.2bcf per day of natural gas. The topsides of the platform feature four deck levels and weigh nearly 10,000t.
The five subsea wells have a flowing capability of 250MMcf/d of natural gas, each. Noble Energy made two agreements in December 2009 to supply the produced natural gas at Tamar. The agreements were expected to generate a revenue of $10.5bn.
The first letter of intent (LoI) was signed on 15 December 2009 with Dalia Power Energies, a private electricity company. As per the LoI, Dalia will receive natural gas from Tamar for 17 years. Dalia will use the natural gas to produce electricity at a gas-fired power plant to be set up at Tzafit by the end of 2014.
The agreement is estimated to generate revenue of $1bn for a supply of 200 billion cubic feet (bcf) of gas. The LoI also has provision to increase the supply up to 700BCF.
The second LoI to sell Tamar natural gas was signed on 28 December 2009 with Israel Electric Corporation (IEC). The 15-year agreement allows IEC to buy 95bcf of gas a year, generating estimated revenue of $9.5bn for the owners of Tamar field.
The contract for subsea umbilicals for the development of Tamar was won by Aker Solutions. The contract for their supply was placed by Noble Energy in April 2010. Under the NKr650m contract, Aker supplied 240km of steel tube umbilicals. The contract also required Aker Solutions to provide subsea engineering and project management services for installing the umbilicals, which were provided from its office in Houston, US.
The umbilicals were supplied by Aker Subsea, a subsidiary of Aker Solutions. They were manufactured at the contractor's facility at Mobile, Alabama,
In April 2010, Noble Energy awarded another contract worth more than NKr300m to Aker Solutions for a complete mono ethylene glycol (MEG) reclamation unit. The unit was employed to assist in removing the blockages in subsea pipelines to be installed at the Tamar field.
The MEG reclamation unit prevents the formation of ice and hydrate and thus avoids the blockage of pipelines. Aker Process Systems, a subsidiary of Aker Solutions, manufactured the reclamation unit. In June 2010, Aker received another order to supply subsea control equipment for the field. The contract was worth Nkr150m.
EMAS was contracted in April 2011 to install umbilicals and subsea equipment for the field. The contract also included supply of subsea suction piles and jumpers.
In May 2011, Alliance Engineering was contracted to design and engineer the Tamar platform and its topsides.
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