Glomar Bores Holes In Seabed In Stormy Strait

Press, Volume CVII, Issue 31500, 14 October 1967, Page 5

Glomar Bores Holes In Seabed In Stormy Strait

[By BILL BAVERSTOCKI Straining to enormous ground tackle, the oil-rig Glomar 111 was weathering a 25-knot blow in the swells of the Roaring Forties as we clambered aboard at midnight.

We had come across Bass Strait from Welshpool in the Glomar’s 150-ton tender, the Point Coupee, and the sea-wise among us wondered how she would tranship her passengers and the heavy drilling gear to the oil rig. It was no problem.

The Point Coupee was laid alongside the Glomar as a Manly ferry makes its berth at the Quay. The spectacle of the two ships grinding together in the open sea in the glare of the Glomar’s floodlights must have been. a weird one for passing ships.

The Bass Strait swell splashed and squirted high between them: rainsqualls cut bitterly across their decks: a ten-ton crane swung giant lengths of drill pipe and casing and tons of cement, drilling mud ingredients, stores and other heavy gear aboard: men bustled about securing it and attending to the straining mooring lines of the Point Coupee. 5000 Feet Down This activity went on until . daylight and all the time high i on the drill floor the rotary : drill spung round, grinding ' the tools deeper and deeper > in the 5000-foot hole the ' Glomar was drilling in the ' bed of the Strait. The drilling crew, splashed I with mud and grease, were 1 hardly aware, of the Point Coupee’s presence. Their full ' attention was on the drill. ! The driller’s eyes never ' moved from the spinning . rotary or his gauges, his crew , of roughnecks performing , their task with the precision , of a well-drilled naval gun’s crew. ; There was oil or gas or at . least indications of them , below the seabed 50 fathoms ; beneath the Glomar’s keel , and they were wildcatting to ; see what the mud would ] bring out of the hole. ; First Offshore Rig But this was a “dry” hole, I like the one that the Glomar I drilled before it and several i later ones. Moved to a lease < off the coast of Gippsland, 1 x the Glomar began probing the ' seabed with dramatic results. 1 One hole struck gas—enough 1 -of it, so Sir Henry Bolte 1 announced, to supply Melbourne for 100 years. Another hole struck gas again and because of a fault in the drilling gear it burst forth with such force that the rig had to be moved while the subterranean wealth she was seeking bubbled to the surface unchecked. Returned to the site, the Glomar controlled the well and it is now awaiting the pipeline that will convey it to fuel-hungry land. The Glomar HI is the first offshore oil rig to work in Australia. Compared with the enormous semi-submerg-ible rigs of the jack-up type she is unimpressive—until you get aboard her. A mud-stained ship of 5000 tons, she looks like an overworked dredge on which a 136-feet high steel tower has been erected, but at work she is a platform from which a 15.000-foot well can be drilled and she can operate in water 600 feet deep. A sister ship worked on the Mohole project. ILS. Contractor" The Glomar travels to the drilling site under her own power. Indeed, she steamed to Australia in 1965 from the United States, her drilling derrick in place and ready to begin work, and weathered two storms, one of hurricane force. She is owned and operated by Global Marine Inc., of United States of America, a contractor which drills wells but does not operate them if and when one strikes oil or gas. She is under contract to Esso Explorations, Australia. After a magnetometer survey made by Aero Services, Ltd, a division of the giant Litton Industries of America, had indicated a drilling site the Glomar was directed to the spot by the aid of Shoran ( Short Range Aid to Navigation), a modern system operated by two specially installed shore stations and accurate to one foot.

The first task in drilling from a ship-shape rig such as the Glomar is to moor her over the site—and for this enormous anchors and cables are used. There are 10 anchors, eight of them are 16,0001 b each and two 23,0001 b. They are laid out by the Point Coupee, two from each bow and two from each quarter and the two to the westward from which the Bass Strait gales blow were backed up by the 23,000 pounders in tandem. Taut Lines

Each anchor has 1500 feet of 2}-inch cable which is shackled to 2f-inch diameter wire rope, leading to individual winches. The wire ropes are wound in so tight it is frightening to watch their straining. A tension meter registering on the bridge showed 28,0001 b of strain on each of the four forward ones while I was aboard but its needle has gone as high as 100,0001 b. The Glomar was moored in

50 fathoms of water. The swell never ceased its slow powerful heave, but the rig rolled little and pitched slightly. The anchors and cables had her snubbed down hard.

Once over the spot where the well will be drilled two problems face the drillers: how to drill from a rolling and pitching deck and where to place the drilling assembly. The second is solved by placing it on the ocean floor. Aided by underwater T.V. cameras the heavy well-head is lowered to the bottom through the “moon pool,” the driller's name for the well in the Glomar’s hull under her drilling deck. On the well-head is the stack of blowout preventers, hydraulically operated devices which control the flow of gas or oil if the drill hits a “gusher.” Telescopic Joint “There is a maze of gear in the moon pool.” When the well casing has been placed it is supported by counterweights and topped by a slip joint which, acting like a telescope, allows the ship to rise and fall with the movement of the swell without dislodging the casing. A ball joint op the well-head permits some sideways movement but not much—a lot depends on the ground tackle. With alt this gear in place drilling begins. The drill on the first length of drill pipe is lowered in the casing and bites into the seabed as the rotary turns it. Drilling mud is pumped down the drill pipe and returns up the casing to the screens which separate the sands and material drilled from the hole. The Glomar is a multi-million-dollar vessel, but this is not apparent from the ship and its gear. What appears to be merely a length of rusty pipe is a core barrel valued at several thousand dollars. Replacing the drilling tools, an operation which takes many hours, the core barrel brings up samples of the rock being drilled—long, four-inch-thick pencils of stone which are studied in the Glomar’s core laboraory, an instru-ment-packed department in which the drilled sands are examined and every foot of the well is logged as it is drilled. $20,000 A Day Apart from the cost of the rig drilling is more expensive offshore. The search for oil in Bass Strait, which has found three fields so far, is costing $20,000 a day. For one reason offshore drilling is slower. Ashore, each length of drill pipe or casing as it is disconnected is stacked in the tower of the rig. but you can't upend hundreds oj/tons of steel pipe in a ship. So when it is necessary to withdraw the tools from the hole each length must be lifted up to the top of the rig, disconnected and lowered to deck

level. Although this is done automatically it slows the operation.

Drilling goes on 24 hours a day, seven days a week. The crews work in tours (oilmen pronounce it “towers”) of 14 days and then have seven days ashore. Übiquitous Mud Below decks the Glomar is a mass of machinery. Pumps for mud, cement and water are everywhere, huge tanks known as “pods” hold reserve mud, and there are surge tanks for mixing it and cement too, when a well has to be “cemented off.” A water-distilling unit supplies 300 gallons of fresh water an hour. Sea water won’t do to mix the mud. Six 600-horsepower diesels are working most of the day and night providing power for the rotary, the draw works, air-compressors, lighting and heating generators and even the galley. Mud is everywhere. It gushes out of the drill pipe and blows about in the chill wind when another joint of pipe is added as the drill bites deeper into the ground. Spray flies over the ship occasionally in the squalls. Busy Captain On the bridge the Glomar’s captain scans a range of instruments—an anemometer, the tension meters on the anchor cables, a wind direction device and his compass. Radio crackles with weather reports, and telephones to the Welshpool base, various parts of the rig, even the tenders and helicopter, which makes daily trips to the rig, keep him fully occupied.

Offshore drillers work hard but off duty they live well. From the mud, seawater and biting wind of the deck you step into heated, immaculately clean living quarters. Accommodation is comfortable, even lavish. There are bathrooms with ample hot water and a laundry with washing and drying machines to remove the mud and grease from working clothes. A noticeable feature of the Glomar’s crew is a complete absence of any distinction. They are served cafeteria fashion and captain, toolpusher and visiting executives sit down beside .muddy roughnecks snatching a hasty meal in the few minutes they can spare from the drilling deck. There’s no saluting and nobody gets called ‘‘Sir.” The visitor gets the impression the Glomar’s _ men are there with one object— to bore ahole in the seabed. There’s no time for frills.but they’re a friendly crowd, ready to discuss their work and explain what’s going on.. It’s like prospecting. You’re living in hopes of a strike.— Copyright, 1967, Associated Newspapers Feature Services.