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Missing JAPEX Wells Found After 48 years


It’s not often I get a shock while working with our Indonesia data set, but finding details of two offshore wells of which I was unaware was a pleasant surprise.

As part of an ongoing update of wells in North Sumatra, I have been researching wells drilled by JAPEX between 1968-1969 in the shallow waters of the Malacca Strait. This was a strange period in terms of oil company activity reporting, before the establishment of in-country and regional scout checks, so sometimes data is scarce or even absent. Much of the data from this period has come my way through trade with like minded “old timers” in SE Asia and among this was a very nondescript two-page typewritten well report misfiled under the misnamed well folder ONS E-1 (referring to well “Offshore North Sumatra E-1”).

Whilst researching the E-1 well (supposedly drilled in 1970) I noticed discrepancies in the well name, dates and rig used and then the penny dropped – I was looking at previously undocumented wells! With the discovery of “Offshore Pangkalan Susu 1 and 1A” (on the “E” structure) we can now put back the start of the JAPEX offshore drilling campaign to April 1968 rather than the previously established September 1968.

Offshore Oil and Gas Pangkalan Susu

It transpires that the well was spudded in 24m of water using the WODECO “MV Torry” drillship and drilled to 1,068m before heavy seas shifted the rig and the well had to be abandoned. The well was re-spudded and subsequently drilled to TD at 1,681m and abandoned as a dry hole on 5 July 1968.

The “Torry” was then replaced by Zapata’s “Investigator” and “Nola III” barges for the remainder of the JAPEX drilling campaign, including four wells on the ill-fated “Gurame” structure further to the north offshore Aceh, where well A-1 blew out with the resulting fire lasting “several months” (but that’s another story).
All in all a very interesting drilling program but ultimately with negative results, but now we have the complete picture.

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Mark Harris

Mark Harris graduated from Kingston Polytechnic with a BSc in Geology in 1985. After working in an oil and gas data storage company in SE London, he joined EXLOG in 1988, based in UK and working on and offshore in UK, Denmark, Netherlands, Italy, Gabon, Pakistan and Tunisia. Mark then pursued a MSc in Petroleum Geology at RSM, London and graduated in 1992. In 1994, Mark joined IEDS to work on Indonesian non-exclusive reports. After 18 months in Tetbury he was transferred to Singapore. Specialising in SE Asia, particularlty Indonesia, and having survived the IEDS/Petroconsultants merger under IHS, he eventually left to form his own company, Geosolutions Asia, in May 2006. In September 2009, this was absorbed into the fledgling DI International under the DrillingInfo umbrella.

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