Laney directional drilling completes record setting drill.

A directional drill to install a portion of a natural gas pipeline from Bolivia to Brazil has resulted in a new-world record for Laney Directional Drilling Inc., Humble, TX.

The record-setting drill came during a river crossing on the Yacuiba-Rio Grande (GASYRG) pipeline being built

The Yacuiba-Rio Grande Pipeline is an essential link in the chain of projects to help Bolivian gas play a leading role in the South American market. Pipeline projects like this are Bolivia's main hope for future economic growth and increasing natural gas exports to become a major energy hub for South America's Southern Cone in the coming years.

The gas line route passes through 49 rural communities and traverses a mixture of populated, semi-populated and unpopulated territories. The route also traverses environmentally sensitive lowland areas and pristine forests. Environmental and safety concerns relating to the project' caused Petrobras to take steps early on to address these issues. The pipeline is laid underground in a two-meter deep trench. Every 21 miles, automatic closing valves are installed to guarantee the maximum safety in its operations. The program also includes services to return pristine areas to their original condition.

The Yacuiba-Rio Grande pipeline, which carries a price tag estimated at $350 million, will have an initial design transport capacity of 11MM cm/d. The pipeline will transport gas from the Petrobras operated San Alberto and San Antonio fields to the Rio Grande plant in Santa Cruz de la Sierra.

Challenging river crossing

Under a joint venture agreement between Bolinter Construcciones Petroleras S.A. and Laney Directional Drilling, their crews were required to make two directionally drilled crossings of the Rio Grande and Parapeti rivers. The contract also covered the design and engineering. The Rio Grande Crossing set a record.

To complete the Rio Grande drill, Laney crews drilled through silts, sands and clays over the entire length of the drill and pulled back 6,575 feet of 32-inch diameter steel pipe.

"The notable thing about the Rio Grande crossing is its length, 6,575 feet, and overall pipe size, 32-inch in diameter," said Grady Bell, a Laney engineer/estimator. "To my knowledge, this is the largest, longest pipe ever installed through a directional drill."

Shortly after winning the contract, Laney mobilized two of its self-manufactured 800,000-pound directional drilling rig, LDD Rig 14 and LDD Rig 17, to Bolivia. On Oct. 10, 2002, Laney's crews set up on the Rio Grande site, performed the necessary survey work and started the pilot bore and a series of backreams in preparation for pulling back the large diameter pipe.

The record setting drill under the Rio Grande was not devoid of problems. The jetted nine-inch pilot bore that reached a total depth of 84 feet was completed in just four days. Crews reported that the pipe string torque remained so low during the drill that there was no need to use the casing that had been brought to the site.

In preparation for reaming operations, the downhole assembly was removed. Initially, a 20-inch flycutter was used. This was followed with 36-inch diameter and 48-inch diameter reaming passes. Next, a 42-inch swab was pulled through the hole in preparation for the final pipe pullback.

Also in conjunction with this phase, crews with Bolinter were working to find sufficient space to string the 6,575 feet of pipe and placed it on rollers in preparation for final line pull-in. Bell pointed out that Bolinter's crews were also charged with welding, testing and pipe coating operations. Other prep work included buoyancy control pipe placement and filling the pipeline with water during to the pullback.

The pullback started slowly and continued well until approximately 85 percent of the way through. With only 12 joints remaining to be pulled into place, the large diameter pipe became immobilized. This posed a major challenge not only because the pullback was less than 400 feet from completion, the pipe was too deep to dig up and tie-in.

To solve the problem, Laney's Project Manager Doug Tise, Superintendent Wayne Robin, Driller Michael "Junior" Marchbanks, and Surveyor David "Easy" Parker, called on their many years of drilling experience.

Looking to tools available in its equipment arsenal on site, the initial solution was first thought to be to combine the power of the drilling rig with the percussive action of an 18-inch diameter pneumatic Grundoram from TT Technologies, Aurora, IL. When this proved unsuccessful, a larger Laney owned 24-inch diameter Grundoram was airfreighted in from Texas.

From the time the pipe became stuck until the 24-inch pipe-ramming device arrived on site and was welded in place and ready to go, 12 days had elapsed. Bell said, "After about four hours the hammer was able to help free the stuck pipe and the drill rig pulled the pipe unassisted for the final few joints. The Rio Grande crossing was successfully completed in six weeks."

Parapeti River crossing

The second crossing on the project involved a 5,414-foot bore under the Parapeti River.

Since Laney had mobilized two of its self-manufactured drilling rigs to Bolivia for the project, as soon as the pilot hole for the Rio Grande crossing was completed, a second crew began work on the Parapeti crossing using Laney Rig 17.

According to Bell, on both crossings crews installed 32-inch diameter X-70 steel pipe that had a 0.688 WT and was fusion bonded epoxy (FBE) coated.

Bell said at this location crews found different soil conditions. There was a high percentage of gravel in the silts, sand and clays soil. "This obstacle was overcome by installing 745 feet of 10-inch steel casing that we had on site."

The pilot bore was started on Oct. 20, 2002. Final pull-in of the 5,414 feet of steel pipe was completed in about five weeks.

Laney's personnel on this crossing included Superintendent John Dagenhart, Driller Steve Dodd and Surveyor Parker who was also involved in the Rio Grande crossing.

"The key to a successful project is to anticipate all possible problems," said Bell, "The personnel, pipeline expertise and superior equipment made these two tough river crossings possible."

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