Drillers use mobile drilling rigs, multinational workforce, to improve operations

June 22, 1998
Three Super-Kenworth trucks are moving Santa Fe Rig 160 (Kuwaiti Rig 7), mast up. Before this system was introduced, rig moves took as long as 7 days. Now, Santa Fe can move a rig in 18 hr over a distance of 15 km (Fig. 1). (Photo courtesy of Santa Fe) A motivated, multinational workforce has achieved extraordinary gains in drilling efficiencies by using highly mobile drilling rigs to deal with tough desert and geologic conditions.

Kuwait drilling operations-1

Dean E. Gaddy
Drilling Editor
Three Super-Kenworth trucks are moving Santa Fe Rig 160 (Kuwaiti Rig 7), mast up. Before this system was introduced, rig moves took as long as 7 days. Now, Santa Fe can move a rig in 18 hr over a distance of 15 km (Fig. 1). (Photo courtesy of Santa Fe)
A motivated, multinational workforce has achieved extraordinary gains in drilling efficiencies by using highly mobile drilling rigs to deal with tough desert and geologic conditions.

This first part of a two-part series describes three classes of drilling rigs designed for fast rig moves, the makeup of a flexible, multinational workforce, and further provides details on dealing with tough drilling conditions.

The second part will cover exploratory drilling and future drilling plans for a country that holds 9% of the world's proven oil reserves.

Mobile drilling rigs

Santa Fe International Inc., a Dallas-based company that operates a worldwide fleet of 71 rigs, uses a variety of rig designs to improve moving efficiency, both on and offshore. In Kuwait, the company uses three desert drilling-rig moving systems:
  1. Integral-wheel complex
  2. Skid-beam trailer
  3. Telescoping derrick.
Currently, Santa Fe's local rig fleet consists of eight rigs: five that operate within Kuwait itself, and three that operate in the Partitioned Neutral Zone (PNZ). In total, there are now nine rigs operating in Kuwait, with the addition of an Admasco rig that spudded-in last month. Santa Fe has been the sole contractor in Kuwait since 1982.

Integral-wheel complex

The integral-wheel complex, designed by Dreco Energy Services Inc., is used by two of Santa Fe's rigs and was first used in Kuwait about 7 years ago ( Table 1 [89,402 bytes]). These rigs are normally moved mast-up utilizing three, six-wheel drive, Super-Kenworth trucks. A single prime mover, pinned to the rig with a tow bar, pulls from the front, while two additional trucks push from behind ( Fig. 1 [13,986 bytes]). Pin connections are designed to handle deflections of 4-5° while moving down rough desert roads.

These rigs can be towed backwards or forward. When moving on the road, the back tires are normally locked while the front tires are free to turn along with the tow truck.

The four sets of dual tires on each rig, each of which are 36 in. wide by 8 ft tall, can be independently controlled for exact positioning over well heads or to turn sharp corners. In addition, each wheel can be individually locked. A manually operated, skid-mounted, hydraulic power unit (HPU) applies fluid to the wheel cylinders for steering.

Although the rigs' substructures are 30-ft tall, the 40-ft distance between each tire provides excellent stability during rig moves. The structural design embodies a fixed-lift system consisting of a lift beam, hydraulic lift cylinders, and the HPU. The whole drill floor and mast are jacked up against the lift beam and suspension system by stroking the lift cylinders (Fig. 2 [115,640 bytes]).

This system picks up the entire rig with the mast in a vertical position. The process is a very quick operation and saves the effort of laying down the derrick, disassembling the substructure, and transferring additional loads onto flatbed trucks.

Skid-beam system

The skid-beam system, currently used on three of Santa Fe's rigs, was first used in Kuwait about 2 years ago. Basically, the system works as a trailer. When it comes time to move, the skid beam trailer is rolled under the substructure and pinned into place through a series of bolts and pins ( Fig. 3 [7,773 bytes]).

Next, the rig is jacked up using the HPU, and braces are pinned in next to the wheels. These rigs have front and rear-wheel hydraulic steering capabilities.

Two Kenworths are hooked up in the front for pulling. Under rough conditions, a dozer is used to push from the back. According to Mike Howe, transport general superintendent for Santa Fe, Rig 3, a 3,000-hp unit rated to 30,000 ft, "may be the largest land rig in the world that can be moved mast up."

The skid-beam trailer for Rigs 155 and 158 have eight tires each, measuring 40-in. wide by 10 ft tall. A single tire costs $30,000 (Fig. 4 [7,439 bytes]). Rig 102 has the same type of system, but smaller tires, measuring 36 in. by 8 ft tall. "The skid-beam system saves 4-5 days in moving," Howe said.

Telescoping derrick

The telescoping derrick, a single-trailer system, is employed on the remainder of Santa Fe's three rigs in the Wafrah (PNZ) and Umm Gudair fields (southern Kuwait). According to Vinot Desai, manager of engineering for Dreco Inc., "these rigs are specifically designed to move fast."

Rigging down consists of scoping the upper section of the mast (crown section) down into the base section by means of a wire line reaving system and hydraulic winch. Once the top section is inside the base, two hydraulic cylinders lay the whole derrick over onto the headache rack (Fig. 5 [8,160 bytes] and Fig. 6 [96,238 bytes]).

Next, the subbase jacks are used to jack up the substructure which is then pinned into the traveling position. Once pinned, the jacks are retracted and the front end is hooked onto the fifth wheel prime mover.

Moving efficiencies

Through the use of these mobile desert-drilling rigs, Santa Fe has attained exceptional cost savings by improving moving efficiencies. For example, from 1995 to 1997, Rig 8 improved its moving time by 20 hr (integral wheel), Rig 20 by 14 hr (skid beam), and Rig 1 by 8 hr (telescoping derrick), all within a distance of 30 km ( Fig. 7 [72,364 bytes]).

The newer integral wheel and skid-beam systems provided higher incremental improvements in moving efficiency achieved through the learning curve. The telescoping derrick is a much older concept and has been in use for decades, thus incremental improvements are not as great.

Nevertheless, according to Jerry Hutchison, drilling superintendent for Santa Fe, the telescoping rigs are still exceptionally efficient. "Even on our 1,000 hp, mast-down rigs used in the Wafrah, they average 18 hr a move, from release to spud. They're packaged well and we've got good people moving them," he said.

However, a mast-up, integral-wheel system can also achieve similar rig move efficiencies. "With a 1,500-hp rig, we typically average a mast-up move over a distance of 0-15 km within 18 hr on average. On a good release, it might be 14 hr," said Gary Bauer, general manager for Santa Fe.

One advantage that a telescoping rig has over integral-wheel and skid-beam systems is travel speed. A telescoping rig can be towed at speeds greater than 25 km/hr, depending on road conditions. Factors that limit towing speed are the size and weight of the loads, road conditions, and heat buildup in the tires.

In relation, an integral-wheel complex can be towed at 15 km/hr mast-up; while a skid-beam rig can only obtain 4-8 km/hr. Skid-beam mast-up rig moves are limited to in-field moves because it becomes faster to lay the derrick down, thereby achieving faster road speeds when moving cross country.

Self sufficiency

Drilling operations in Kuwait are almost totally self-sufficient. In the Al-Ahmadi oil field complex near Kuwait Oil Co.'s (KOC) headquarters, Santa Fe has a yard filled with drill pipe, stabilizers, swivels, and other ancillary equipment.

In addition, Santa Fe's machine shop and mechanics combine to make a world-class, autonomous facility. "We are totally independent when it comes to rebuilding our engines, pumps, and other equipment," Hutchison said. "This is a unique aspect of our operations here," Bauer said, "For instance in the U.S., if a motor goes down, service and support are easy to obtain because of the well-developed infrastructure. However, in Kuwait, you have to depend upon yourself because we are isolated from the outside world."

Drilling operations are essentially turnkey, especially in the sense of rig moves. "The only thing we are not doing is taking control of drilling the wells," Bauer said. Santa Fe even hauls all well consumables that include casing, wellheads, and other well supplies for KOC's wells.

Earlier this year, a 3-yr-contract extension for Santa Fe's five in-country rigs was finalized between KOC and Santa Fe. In addition, responsibilities were added to its rig-move obligations, including site construction. To meet these commitments, Santa Fe has purchased an additional 69 pieces of moving equipment including all-terrain cranes, water trucks, forklifts, and fuel tanker trailers.

Benchmarking

Benchmarking plays a key role in cost reduction for Santa Fe. "We have all sorts of benchmarking systems going on. We benchmark moving time, down time, trip time, drill bit runs, nipple up time, slip time on a connection, or even the time it takes to make up a joint of casing from one joint to the next," said Miles Sheldon, vice-president and Middle East area manager for Santa Fe.

Benchmarking not only allows Santa Fe to determine its strengths and weaknesses for each of its drilling activities, but also promotes competition among the rig crews. Superintendents benchmark rigs against each other in similar fields. "When we see Crew A making a connection in X amount of time, and Crew B making it in Y amount of time [faster], we have to ask ourselves, what's the problem, what are we doing different?" Hutchison said.

Toolpushers play a key role in transferring knowledge from crew-to-crew. "A toolpusher will watch one crew use it [benchmarking technique], then pass tips on to the other crews," said Saddoun Abbasi, drilling and workover superintendent for Santa Fe.

And, what's good for the contractor is almost certainly going to be good for the operator. "What's great about it is the clients are very responsive to it. This goes a long ways towards their objectives as well," Bauer said.

Multinational teamwork

While other companies are just now realizing the advantages of utilizing a multinational workforce, Santa Fe has definitely been a pioneer of multinational teamwork for quite some time (Fig. 7).

At the IADC/SPE Drilling Conference in Dallas last March, George Boykin, general manager of worldwide drilling for Amoco Corp. explained that in the past, "being a global drilling organization meant operating in many different countries around the world."

Today, this concept has changed: "Being a global drilling organization means having a staff from many different countries contributing in significant roles throughout the organization regardless of location," Boykin said. Amoco believes that the globalization of the drilling organization is the key to continued success.

"The reasons are many, but they all boil down to one underlying premise: It makes good business sense." Boykin credited Santa Fe with being a model of workforce diversity during his presentation at the conference.

With Santa Fe, a company that employs 5,700 people from 48 countries and operates in West Africa, Southeast Asia, North Africa, Middle East, North Sea, North America, and Venezuela, this leads to numerous logistical problems both in relation to its workforce and entry into international markets.

These include:

  • Agent, sponsor, partner requirements
  • Customs duties-Rig and resupply
  • Taxes-Income, property, personnel
  • Labor issues-visa requirements, training of locals, local unions
  • Legal structure-local incorporation, foreign entity
  • Political risks-expropriation, nationalization
  • Currency-repatriation of profits, currency fluctuation, exchange rates
  • Hostilities-revolution, war, evacuation of personnel, equipment removal
  • Change of government leadership.
Expanded infrastructure support is also a prime consideration. For instance, in Kuwait, Venezuela, and other international land operations, it is necessary to have autonomous operations including a large inventory of spare parts, camps for land rigs, and transportation equipment.

In addition, governments often require local hiring quotas. In Kuwait, KOC requires that 10% of those in certain job categories should be Kuwaiti.

Flexible workforce

In Kuwait alone, Santa Fe has more than 600 employees from 20 countries ( Table 2 [44,458 bytes]). "This mix does not happen by accident," Sheldon said. For example, Santa Fe has a large training center in Egypt that also serves as a major base of operations. Yet, it would be impossible for Santa Fe to use the Egyptian labor pool as a primary source for labor.

One important reason to maintain a disparate workforce is because many countries place entry restrictions, disallowing certain workers from foreign countries to obtain work visas. Thus, a company must have a diverse labor pool to draw upon. To achieve a flexible workforce, Santa Fe currently recruits from Thailand, the Philippines, India, and many other countries.

"It's not always the easiest thing to do because of the cultural and communication differences, but by necessity, to be a competitive workforce and to have the flexibility to quickly move a rig to one area or another, you have to do it," Sheldon noted.

"English serves as the primary mode of communications," Howe said. "On most of our rigs, we have mixed crews and there must be a common language, especially during the drilling operation."

Turnover on Santa Fe's rigs is minimal. "Promotion from within" has provided an incentive for every hand, ranging from the floorhand to drilling superintendent to stick around, Bauer explained. "The guys down the ladder, where there is usually less motivation, are keen to move up because there are opportunities," he said.

In the PNZ, where Santa Fe recently spudded-in a new rig, a benchmark well was set on its fourth hole. By bringing personnel up through the ranks, "you are able to place strong rig crews on new rigs where traditionally you would have a very tough time," he said.

"We probably have less turnover than an individual rig in the U.S. We have roughnecks that have been with us 5 to 6 years on the same rig," Hutchison said. For these workers, it means long-term work, and social relationships will be developed across cultural boundaries.

Even the operational managers are "long termers." Bauer, Hutchison, Howe, and Abbasi are all 20-year, Middle East veterans while Sheldon grew up in Kuwait as a boy.

Of course, safety is an ever-constant issue for Santa Fe, which is promoted by safety awareness and crew longevity. Staff and crew members attend regular safety classes on well control at Santa Fe's IWCF certified training center at its Al Ahmadi office and there are compulsory, weekly safety meetings held at the rig site.

"We have a rig in Oman, Rig 150, that just completed 7 years without a lost time accident, and that rig moves about every month," Sheldon said. "Of the 70 crew members, 26 have been with that rig 7 years."

Overcoming drilling problems

Although horizontal and multilateral drilling technologies are in wide use around the world, Kuwait has found no major need to use them in current drilling programs. Reservoirs like the Burgan are world class, and applications of such technologies would not vary production by much even if they were applied.

Even after the war, with 603 wells flowing wide open for more than 6 months, the reservoir drop was barely measurable. "In the 40 to 50 years of production, we've only had a 20 psi drop," said A. Hussain Shehab, manager of drilling operations for KOC.

However, there have been occasional stabs at drilling horizontal wells around the country in addition to a water-injection pilot project applied to one of Kuwait's northern fields. Also, the interpretation of 3D seismic surveys, run over every field in Kuwait, is in its final stages. Once these results are in, future horizontal drilling and water injection programs will be instituted, Shehab said.

Nonetheless, although Kuwait does not use state-of-the-art drilling technologies, drillers face very tough drilling conditions.

There are two major types of wells in Kuwait:

  • Shallow Tertiary and Cretaceous wells
  • Deep, overpressured Jurassic wells.
One of the biggest problems is simultaneously dealing with lost circulation zones while maintaining well control through horizons replete with gas pockets. For instance, in the PNZ, there is a shallow gas zone just below 600 ft. However, just above this zone, at about 575 ft, lost circulation is a very common problem.

This problem repeats itself again and again. "At times it becomes necessary to drill these zones blind, "Bauer said.

"You drill, you keep water flowing down the annulus while drilling, and you watch the monitor closely. If that pump goes down even for a minute, that well is flowing or blowing," Hutchison said.

Fortunately, Santa Fe's rigs are designed to deal with these conditions. Centrifugal pumps force fluid down the backside and each rig is set up with two 10-in. flow lines. "I'll guarantee when it flows, it makes you a believer in mother nature," Bauer said.

In the deeper Jurassic horizons, drilling becomes even more complicated. "They talk about high-pressure/high-temperature wells in the North Sea, and how they are using breakthrough technology. We've been drilling these for more than 15 years, it's nothing new around here, nor in Saudi Arabia," Bauer said.

These zones require 18 ppg muds and higher. "We've been at 22,000 ft drilling with 21 ppg mud," Abbasi said. The deeper wells require six or seven casing strings because of the thief zones, isolated gas pockets, and overpressured zones.

In the end, when it comes to dealing with overpressured zones and lost circulation, it takes a combination of technology and experienced crew members to effectively deal with geological conditions unique to Middle East countries.

Copyright 1998 Oil & Gas Journal. All Rights Reserved.