Ku-Maloob-Zaap Field, Gulf of Mexico, Mexico

In 2002, the Mexican state oil company Pemex embarked on an eight-year project to boost heavy crude output from its Ku-Maloob-Zaap oilfield in the Bay of Campeche, Gulf of Mexico.

A 42.2bn peso investment was aimed at raising the level of heavy crude output from 329,000bpd of oil and 172.1mmscf/d of gas to 800,000bpd and over 300mmscf/d by by 2011 to offset the production drop Cantarell, one of the world's largest oilfields and responsible for some 60% of the Mexico's total crude production.

Ku-Maloob-Zaap is located off the coast of Tabasco and Campeche, 105km (65 miles) northeast of Ciudad del Carmen, Campeche. It covers an area of 121km² (47 square miles) and includes a number of fields, including Ku, Maloob, Zaap and Zazil-Ha.

Ku, Maloob and Zaap fields produce from the Kimmeridgian, Lower Paleocene-Upper Cretaceous and Middle Eocene reservoirs. Total reserves of the field have been put at 4.9 billion barrels. A key strategy is injecting natural gas and nitrogen into wells to provide an enhanced oil recovery drive. The field lies in 100m of water.

KU-MALOOB-ZAAP DEVELOPMENT

The development plans envisage the drilling of 103 wells, four of which will be injectors, and the construction of 17 new platforms – seven drilling, four production, four accommodation, one telecommunication and one processing. There will also be 42 new pipelines totalling 189km in length.

The Ku-Maloob-Zaap field development was given a boost in 2007, with the first-ever a shipshape production floater in the Gulf of Mexico. Oslo-based owner-operator BW Offshore converted the ultralarge crude carrier Berge Enterprise into a 2.2 million barrel capacity Yuum K'ak' Naab (Lord of the Sea) FPSO – the largest oil throughput of any FPSO presently afloat and the third largest production capacity. It can produce 200,000bpd of crude oil and 120 million cubic feet of natural gas a day.

The vessel is designed for throughput of 600,000bpd of oil and 120mmscf/d of gas is expected to act as a hub and export terminal for the next 15 years in the Bay of Campeche. After processing, the oil and gas will be transported ashore via tankers and transport pipelines.

FPSO

Yuum K'ak' Naab was converted at the Sembawang Shipyard in Singapore by Sembcorp Marine under an $88m contract. The FPSO 340m long, 65m wide, 31.5m tall and has a deadweight of 360,700dwt.

Originally built by Mitsui, the conversion project encompassed the inclusion of an internal disconnectable submerged turret system provided by APL. This 12-line mooring system is connected to 35m pile anchors, and the wellstream enters via eight 15in flexible risers and midwater arch.

Other changes included the installation of a number of topsides modules, the expansion of the living quarters to 110 personnel and a flare tower.

A feature of the KMZ fields is that the oils have different viscosities. Ku has an API of 22°, while the Maloob and Zaap fields have an API of 12°. The Yuum K'ak' Naab therefore has a segregated storage facilities with one tank able to store one million barrels of blended crude similar in chemistry to Cantarell's 21°API, known as Maya blend.

To facilitate the position as a hub, the design of the facilities allows the processing of 250,000bpd of medium viscosity and 300,000bpd of heavy viscosity oil which is imported through one 30in and one 36in pipeline. There are also six separate compartments allocated to high and medium-viscosity well fluids. The processing systems layout was designed by Kanfa / Grenland.

The compression, fuel gas amine treatment and separation modules were provided by Lamprell while Dresser supplied two LM 2500 25MW dual-fuel turbines. The power generators came from Dresser-Rand and waste heat recovery units were supplied by Kanfa-Tec.

The fiscal oil offloading metering system, provided by Daniels, was based on a four path ultrasonic Caldon meter with a separate prover loop. Three utility modules were provided by Unicon / GSI while Emerson provided the vessel's safety systems and process controls.

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