Logging is personal at Schlumberger. It grew from the dedication of Conrad and Marcel Schlumberger to technology through bathtub experiments in the back yard through the first downhole application into an industry that helped operators find billions of barrels of oil and trillions of cubic feet of gas that might otherwise have been overlooked.

Paul Schlumberger, already well-to-do from a thriving leather goods business, had sent his

This early logging kit in the Schlumberger museum showed a simple setup with the black box that measured resistivity and reels that handled the cables. (Photos by Don Lyle)
sons to the best technological schools in France. Conrad, the inventor, had an idea that an electrical current sent through the earth and returned to receivers could help identify subsurface objects through their resistance to the flow of the current. Using ore samples with different conductivities in a bathtub filled with mud, the brothers were able to outline the shape of objects by means of equipotential measurements traced on paper stretched over the rim of the tub.

Their father drew up a contract. It read (in English), “I agree to disburse to my sons, Conrad and Marcel, the funds necessary for research study in view of determining the nature of the subsurface in amount not exceeding 500,000 francs…they must devote themselves to it entirely. The scientific interest in research must take precedence over financial interests.”
His sons honored that contract devoting many hours to measurements from the surface.
From the bathtub experiments starting around 1911, Marcel and Conrad expanded to their first truck in 1912. Surface measurements were helping find anticlines, faults, metal ore deposits, salt domes and other structures.

They started a worldwide patent barrage that included Brazil and Mexico in 1913, Czechoslovakia in 1923 and the Belgian Congo the following year. By 1935, they had patents on every continent but Australia.

During this period of experimentation and development, over lunch one day, Conrad Schlumberger shared the success of these surface measurements with a classmate from the Ecole Polytechnique. The colleague, who ran a drilling company, said he would be more interested if the measurements were taken in his well bores.

By 1921 the brothers were taking electrical measurements at the bottom of wells to establish correlations with the surface measurements. That led to the idea that they might be able to move the logging equipment up the borehole for a detailed profile of a well. Conrad Schlumberger, a board member of the Pechelbronn oilfield company in Alsace, quickly got permission to test the new equipment on a working well, according to the records of Roger Jost, who ran the first well log on September 5, 1927, with Henri-Georges Doll, who was Conrad Schlumberger’s son-in-law, and Charles Scheibli, an engineer with the logging company, then called Société de Prospection Électrique, nicknamed Pros. The three men lowered the logging sonde (fish) to 915 ft (279 m) in the Diefenbach 2905 well and used a 36-volt battery to send electricity down the hole.

Translated, Jost wrote, “I am operating the potentiometer: measurements of current and voltage difference. Doll, in front of me, writes down the values I give him onto a handbook. Two quick computations on his sliding rule and the triumph of this first measure point resounds: It works! We stop every meter, going up, and this over 140 m (459 ft) For a while, the resistivity changes have been minimal, because the sonde had been surveying calcareous shales, then the resistivity began to dance because rock type was changing. Doll quickly adds the points on the chart paper and draws the curve.

“After this period of trial and error, we are now confident and our three faces are glowing with satisfaction… Scheibli is everywhere. He looks after the sheaves, the wires, the cable drum.”

The whole operation took 5 hours.

Most of the operation went well, but the team did encounter a learning experience. According to Jost, “We continued till we reached the casing shoe. Then we pulled the tool back to surface and rigged down. We removed the lead ballast from the sonde hanging from the derrick. Splash! The drilling mud that was filling the bakelite tubes poured down. I believe that Doll received the most extensive shower from head to toe.”

Doll left for Paris to report to the Schlumberger brothers, while Schiebli and Jost continued logging wells in the field.

“On the third day, I remember that we went into some kind of trouble. We had dropped the
People celebrating the 80th anniversary of downhole logging gathered at the monument to the first logging job at Pechelbronn in Alsace, France.
wires in the well and when we hooked them back to the drum, it became a ball of wires. A kitten would not have done worse with a ball of wool. The same day, we added some adhesive tape every 10 or 15 m (32 to 49 ft) around the wires so that they would behave in a more orderly manner,” concluded Jost.

This event marked a turning point for the fledgling oil and gas industry. “Electric logs showed (the location of) oil. Before then, logging was used as a correlation tool. A revolution in the oil business was under way,” said Ian Strecker, former executive vice president and chief technology officer for Schlumberger, during his keynote presentation at the Société pour l’Avancement de l’Interprétation des Diagraphies (SAID) meeting, the French chapter of the Society of Petrophysicists and Well Log Analysts (SPWLA).

SAID honors logging
Some 80 people celebrated the first downhole logging celebration this year at a special SAID conference in Paris attended by active members, industry veterans and students under the direction of Schlumberger retiree Philippe Theys. It was particularly significant for Schlumberger, since the company, with its worldwide patents, held a monopoly on logging until 1938.

Among the veterans, the conversation with strangers inevitably started with the questions, “Where (in the world) did you take your training?” The loggers would reel off the names of exotic, often remote and dangerous places they had taken their logging tools. Among the long-timers, many of them retired, the conversation would come around to personal ties with the Schlumberger brothers, Doll and other pioneers.

A favorite story recalls the time rival Halliburton had gotten logging patents from Humble Oil and started a competing logging business. This was a particularly grating issue, since Erle Halliburton had offered to buy the company for $10 million as World War II smothered operations everywhere in the world except the United States. Marcel Schlumberger turned him down flat, according to the book “The Art of Corporate Success: The Story of Schlumberger” (1984) authored by Ken Auletta.

Schlumberger sued Halliburton in Houston and won the first court round under a decision by Judge Thomas Kennerly. A higher court later reversed the decision on appeal. According to the company veterans, Marcel Schlumberger fell back on a couch in despair when he heard the news. Doll, however, said something like, “Fine. We’ve lost the patent protection. Now, we’ve just got to be better — we will stay ahead through technical innovation.”

Leading the day-long SAID meeting, which featured 12 technical presentations, Strecker looked at the progress the industry has made and how technology drives efficiency. Twenty-five percent recovery was the best achievable 50 years ago. Now, rotary steerable drilling equipment and logging-while-drilling tools allow Saudi Aramco to put a main horizontal well bore with eight branches totaling up to 7.6 miles (12.3 km) of well bore precisely in a producing formation. The same technology allows ConocoPhillips to get 60% higher production from its Alpine field on the North Slope of Alaska, he added.

Charles Woodburn, president of Schlumberger Wireline, presented a review of wireline logging technology since that historic day in 1927. By 1929 logs had been run in many countries. The Schlumberger brothers published their first paper on this new technology known as “Electrical Coring” at the International Drilling Congress held in Paris, September 16-23, 1929. Logging technology spread throughout the world in the 1930s.

The next major step in logging compared the physical properties of rock using various new wireline measurements, he added. The company conducted its one-millionth logging operation in 1956. By 1957, the logs gained more sophistication with micrologs, laterologs, induction, sonic, neutron, spectral gamma ray, fluid sampling and other variances.

Through the 1960s, logging operations had grown into production of sensors for use in space by the US National Aeronautics and Space Administration to deep ocean sensors for research and to measuring saturation through casing, Woodburn added.

The triple-combo log measuring resistivity, gamma radiation and neutron density debuted in 1971. The company was working on nuclear magnetic resonance (NMR) imaging in the 1980s, pushed by the technology’s capability of calculating permeability. The company’s Platform Express integrated wireline logging tool came out 10 years before the competition brought a tool into the market that could provide similar measurements in as short a time.

During the same meeting, Jeremy Lofts, director for formation evaluation product lines with INTEQ, a division of Baker Hughes, talked about the value added to the industry following the introduction of logging while drilling (LWD) in the early 1980s. LWD opened the door to real-time drilling operations. Logging tool capabilities have grown to include fluid analysis, high-pressure/high-temperature measurements and logging behind casing.

Formation evaluation tools include resistivity, acoustics, gamma, pressure, temperature and NMR logging. The technology aims at reducing uncertainty in the subsurface and attaining maximum production and access to reserves. The latest technology, he said, is azimuthal resistivity and other techniques that allow the operator to look ahead of the drill bit for pore pressure and formation information.

Touring the frontier
That technology has come a long way from technology viewed by the SAID group as it traveled to the Schlumberger Museum at Crevecoeur in Normandy. The museum displayed the bathtub in which the brothers sank ore samples in mud and drew earth models on paper stretched over the top. It offered examples of hand reels for the wireline and primitive recorders and traced the technology forward to modern logging trucks.

The group also visited the nearby Abbe du Val Richer, the Schlumberger family’s country estate where the brothers conducted many of their early experiments with the bathtub. The following day, the group visited Pechelbronn and the site of the original well log and a nearby museum. The display in the museum refers to the first “electrique carrotage.” Carrotage, or carrot-like, referred to the general shape and look of a core sample and early logs were called electric coring.

That first electric log and the research that led to it created a legacy that remains with Schlumberger through modern times.

Legacy of research
One part of that legacy is in research and development (R&D). The Schlumberger brothers did their own research and development work, and today the company still considers research the backbone of its growth.

It maintains five R&D centers around the world and has 20 technology centers. Those technology centers are tailored to local conditions, and there is little redundancy among them. This year, the company will spend about US $2 million a day on research and development. Even when the industry has fallen on hard times, the company has maintained its financial commitment to R&D.

That characteristic is not strictly traditional, according to Dr. Smaine Zeroug, marketing manager for the Schlumberger Clamart Technology Center. He said it is also good business. Companies that react to short-term turns in the oil and gas market tend to lose continuity of research, and that causes costs to increase when the industry recovers and they have to restart research projects.

Another legacy that has stayed with the company grew from the Schlumberger brothers’ early patenting operations and their early work in establishing logging centers around the world. They opened the doors for local recruiting, often recruiting logging crews from local citizens as they wanted to recruit talent from the countries in which they operated.

“They pioneered the belief that talent is available anyplace in the world,” said Zeroug.
As noted by Strecker in his keynote presentation, the world has produced 1 trillion bbl of oil since the industry became an industry, and it probably will produce reach the 2-trillion-bbl mark by 2030. That still leaves another 4 trillion bbl available for potential production. To reach the maximum number of those barrels, the industry will use the latest geological theories, the newest high-resolution seismic technology, and most of all, it will use the latest generation of the logging tools first used in an oil well in Pechelbronn in 1927.