Jerry Lee provides an overview of Mexico’s Ku-Maloob-Zaap (KMZ) heavy oilfield in the Bay of Campeche.
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Pemex’s Ku-S central processing installation at the Ku-Maloob-Zaap oilfield in the Bay of Campeche offshore Mexico. |
Heavy oils are typically composed of long, high molecular weight compounds. These oils are characterized as having less than 20°API gravity, and low gas-oil-ratio (GOR). The low API and low GOR results in a fluid that is higher in density and very viscous. These qualities are problematic for field production, as the fluid is then less mobile, resulting in greater effort required for extraction; however, heavy oil accounts for triple the volume of reserves as compared to conventional oil and can, therefore, be a significant source of production when fields can be produced economically. Such is the case in the Gulf of Mexico with the Petróleos Mexicanos’ (Pemex) Ku-Maloob-Zaap (KMZ) field.
Found in the Bay of Campeche, KMZ is 150km northeast of Ciudad del Carmen, Campeche, off the coast of Mexico, near the states of Tabasco and Campeche.
KMZ is comprised of five fields: Ku, Maloob, Zaap, Bacab, and Lum and Zazil-Ha. These fields total an area of about 121sq km, and sits below an average 100m water depth. Hydrocarbons are produced from multiple zones: Kimmeridgian, lower Paleocene, upper/middle/lower Cretaceous, and middle Eocene reservoirs [2]. From the main fields, Maloob and Zaap oil is about 13°API while Ku oil is about 22°API [1]. In total, reserves are estimated around 4.9 billion bbl.
Early history
The Ku field was the first of the five fields to be discovered. In 1979, the Ha-1A well discovered hydrocarbons at the Ku field. Production followed in 1981 [2,3]. Following the Ku discovery, Maloob was discovered next in 1984 and Zaap followed in 1991. The field became the second largest producer for Pemex following the Cantarell field, producing an average of 247,000 b/d of crude, and 152.5 MMcf/d of natural gas.
Redevelopment
Taking lessons learned from Cantarell field, Pemex made the decision to redevelop the KMZ field so that it would not suffer the same rapid decline seen at Cantarell. As a result, in 2002, Pemex planned an expansion of the Ku-Maloob-Zaap project that would involve drilling additional wells and pressure maintenance systems for the field. Like the Cantarell field, KMZ utilized nitrogen injection to maintain pressure in the reservoir. The success of the investment has been seen over the years as production tripled from 2004-2013, resulting in KMZ overtaking Cantarell in July 2009 as Mexico’s largest crude producing field. In addition to adding more wells, the 2002 expansion project would include 32 new pipelines and 17 new platforms: separate platforms for telecommunications, production and a compression center, four accommodation platforms, four production platforms, and seven drilling platforms.
Four drilling platforms were contracted to a joint venture between Empresas ICA Sociedad Controladora and Fluor for US$169 million. The platforms were completed in August 2005. Swecomex delivered the Ku-S production platform at the field in 2006. That same year saw the installation of the two accommodation platforms, HA-KU-S and HA-KU-M by Keppel. Production platform, PB-KU-A2, was delivered in October 2007 by Dragados Offshore.
Further investment was made at the field in 2005 when Pemex opted to add a floating production storage and offloading (FPSO) vessel to the field. The Yuum K’ak naab FPSO, the first in the Gulf of Mexico (Petrobras’ Cascade/Chinook took the title of first FPSO in the US Gulf of Mexico in 2011), began production on 18 June 2007. The $758 million vessel, owned and operated by BW Offshore was contracted with Pemex for 15 years. This vessel has the capability to handle 600,000 bo/d of both oil types, process 200,000 bo/d, and export gas. By 2008, average field production stood at 706,100 b/d of crude, and 272.8 MMcf/d of natural gas.
Nitrogen injection began at KMZ in 2009, along with McDermott’s delivery of the drilling platform, Maloob-C [3]. In 2011, Pemex installed gun barrel technology in the field to improve the quality of crude, an investment of $1.75 million. By 2010, KMZ production averaged 839,200 b/d of crude and later peaked at 927,000 b/d in 2013.
By 2013, KMZ produced an average production of 863,800 b/d of crude, and 405.1 Mcf/d of natural gas, bringing cumulative production to 4.2 billion bbl of crude and 2 Tcf of natural gas. As the top crude producing field, Pemex invested another $2.61 billion in 2014, bringing the fields total development cost to over $20 billion.
Works Cited
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