[USDP-4 drilling: brief daily report] later than Sept. 8, 2003
[USDP-4 drilling: brief daily report] earlier than April 10, 2003

July 25, 2003

The second meeting of Drilling Safety Committee was held in Tokyo this day. The structure in which we carry out drilling hereafter was also discussed and we decided to reinforce it stronger than before. Here, drilling technique and experience of oil companies should be introduced, top-drive drilling in highly inclined trajectory is essential, and larger amount of water is needed to penetrate cavity-rich formations and reduce accidents accompanied with high temperature drilling. Together with this, modification of drilling schedule and money plan was needed.

We reached the conclusion that we can resume drilling in September and penetrate the target within the first half of next year.

July 1-2, 2003

A speical session, "Scientific Drilling and Volcano Structure", was held under organization by J. Eichelberger, S. Nakada, and S. Tait in the IUGG (Sapporo) meeting. Many scientific results from USDP were presented.

June 19, 2003

This year first meeting of Drilling Safety Committee was held in Tokyo on 19 June. The committee involves Shoichi Tanaka (Emeritus Prof. of Univ. Tokyo) as the chairman, specialists from oil drilling, mud circulation, logging companies, volcanic gas chemistry, PI's, and so on. It was agreed that the countermeasure of future drilling is treated in this committee, ignoring the name of the committee. Problem of drilling we met this March and April was shared with the committee members and the countermeasure for future drilling was discussed. Necessity of new drilling strategy and structure was come to an agreement.

April 21, 2003

[Countermeasure meeting]

The meeting consisting of PI's, the contractors (ordering and receiving companies), and the chairman of the Drilling Safety Committee of this project, was held in Tokyo on 21 April. Countermeasure for changed hole during drilling was discussed, including problems related to distinction of operations by the Japanese government and ICDP costs and treatment of the expenses caused by drilling changed hole. The following agreement was reached among them.

Though the 260-m depth was once reached with hole opener in early April, casing pipes of 18-5/8" were not successfully set. This is due to irregular shape of hole around the bottom of the first casing pipe. Then, hole gauging and cleaning with 21" stabilizer and trial of casing set were repeated during mid April. Unfortunately, it became clear that the hole inclination was changed into smaller degree than the planning, although the diameter needed for the casing was performed down to 260 m. It is considered that many cavities once sealed with cementing in the earlier operation were re-opened during this process and bites set at the bottom of stabilizer fell into the cavity, drilling of new hole. Though drillers tried to follow the primary hole by sealing cavities with cementing, PI's stopped their trial on 17 April. We were afraid of more difficult situation produced by their trial. It is easy to suppose that repeating hole opening and gauging in the upper part of this volcano introduces new larger cavities in multiple depths, causing deep trouble. We directed to set 18-5/8" casing pipes down to 167-m depth, and to stop the operation for a while for reconsider the strategy in mid April. The depth of 167 m is the possible level from which we can try the first target after resetting of the drilling trajectory.

Next drilling operation will begin the early July when the Japanese government money becomes available.

[Progress]

22 March Reach to 260-m depth with 12-1/4"

1 April Termination of hole opening with 20" and identification of hole trajectory

6 April Trial of insertion of 18-5/8 casing but incompletion deeper than 70-m depth.

9 April Start of gauging with 21" stabilizer

15 April Completion of gauging down to 264-m depth

16 April Identification of changed hole

18 April Insertion of 18-5/8" casing down to 167-m depth

April 6, 2003

Installation of 20" casing. Due to abnomal loading around the bottom of the first casing, these casing pipes were retreaved. Milling the first casing bottom (shoe) will be tried to widen clearance.

April 5, 2003

	Casing (20") pipes. Photo shows the bottom of deepest pipe. Cement runs through the central hole of the bottom. Upper right is the inner nozzle of cement and lower right is a ball acting as cock.
	Rape blossom and Mount Unzen. Taken near base camp

March 28, 2003

"Science" magazine introduced the conduit drilling at Mount Unzen (USDP project) as Special Science in the March 28 issue (Vol 299, p. 2018). (Click image to move to Science)

March 23, 2003

Hole opener and stabilizer (left) and the assemblage (right).

March 22, 2003

Cherry blossom in Shimabara

Cuttings (mediumu grain) from the depth 150m.

March 1, 2003

Cementing work for strengthening country rocks at KOP on Feb. 25.

February 27, 2003

Down-hole moter (DHM) drilling had gone on from kick-off point of 80-m depth.

Preparation of cementing on Feb. 25.

February 18, 2003

Rotary drilling operation began from 50-m depth.

February 15, 2003

Geologists started cuttings analysis in Shimabara.

February 17, 2003

Conduit drilling started using the 50-m high rig on February 17, 2003.

Conduit drilling (USDP) was reported in "Geotimes" (American Geological Institute): http://www.geotimes.org/feb03/WebExtra021003.html

February 13, 2003

Opening ceremony was held at the rig site of conduit drilling on February 13, 2003.

About 50 attendees are from the MEXT (Ministry of Education, Calture, Sports, Science and Technology), Forest Agency, Ministry of Environment, Nagasaki Prefectural Geovernment, Shimabara City, scientists. Drillers etc. Over 40 press people gathered to report this ceremony.

February 1, 2003

Click to enlarge!

Rig-up for the conduit drilling after air-hammer drilling down to the 50-m depth. Opening ceremony of drilling is scheduled on February 13 on this site. The rig is 50 m high. It had heavy snow in late January.