In 1987, Maersk Oil drilled the world’s first horizontal well equipped with a cemented liner and multiple hydraulically induced, sand propped fractures for drainage and productivity enhancement.
Maersk Oil, together with the service industry, developed the technology to selectively perforate, stimulate and isolate individual zones in horizontal wells, the PSI system, as well as other well technologies.
Maersk Oil has performed more than 550 sand propped fracture operations. More than 190 million pounds of sand has been pumped by filling each fracture with up to 2.1 million pounds of sand. As many as 18 sand propped fractures have been performed in one horizontal well and, in 1991, a world record was set when 12.4 million pounds of sand were pumped into a 5,000 feet long horizontal well. Maersk Oil has furthermore performed more than 160 acid fractures in horizontal wells and Maersk Oil’s technology continues to be progressed. Later innovations include water jetting for stimulation and controlled acid jetting, developed to stimulate very long horizontal well sections outside coiled tubing reach. The controlled acid jet technique employs an uncemented liner with controlled reservoir access, ensuring efficient acid stimulation of the complete horizontal well section. The method has proved not only efficient, but also much faster and much less complicated to install.
In 1993, Regnar, the first field developed in the Danish North Sea using subsea technology, was brought on stream by Maersk Oil. This small satellite field is connected to the host platform by an 18 kilometres long pipeline, where the projected recovery of only 3.3 million barrels of oil necessitated innovative facilities design for an economic development.
Maersk Oil Qatar has in 2008 set a record drilling of the longest well in the world to a length of 40,320 feet (12.3 km). The horizontal section of the well of 35,770 feet (10.9 km) also constitutes a world record. The entire horizontal well section is placed within a reservoir target which is only 20 feet (6 m) thick.
Maersk Oil has pursued a stepwise development of the fields so that new data and technology may rapidly be implemented in further development steps. This has been facilitated by seeking maximum integration and flexibility between different field developments. Hereby, maximum use of existing processing facilities and infrastructure has been possible in each development step. This approach has been the key to obtaining the technically efficient and economic development of the marginal fields and field flank areas encountered in Denmark.
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