Chemistry keeps the black gold gushing, Oilfield chemicals from BASF help in extracting the sought-after raw material crude oil from the ground more efficiently

The Story

Prices for crude oil keep climbing to new record levels, with brief phases of respite usually turning out to be the calm before the next assault on the summit. Bad news, not just for drivers, because the entire world economy depends on the black gold either as an energy source or a raw material for the chemical industry, which in fact consumes only 13 percent of the oil used in Germany. Since the late 1960s, the volume of newly discovered oil deposits has declined sharply although consumption is continuing to rise. Another 50 years, estimates the Association of the German Petroleum Industry, is how long the currently known reserves will last. Admittedly, such estimates are contested among experts. Because no one really knows how much oil the earth’s crust contains. The real question is how much of these subterranean resources can be brought to the surface at a justifiable cost using existing technologies. The pressure in the oil reservoir forces only the first 3 percent of a deposit to the surface, and 10 to 20 percent can be raised with traditional pumping technology. But gaining access to at least part of the remaining oil requires the use of more advanced technologies and support from chemistry.

This is where BASF plays a major role with its full range of oilfield chemicals. “From the first test drill onwards, BASF products accompany the entire production process and allow the deposits to be accessed much more intensively. Only with these materials can we achieve an oilfield yield of 30 percent and more”, explains Dr. Gregor Brodt, responsible for the development and applications technology of oilfield chemicals at BASF. The range of products offered by the Ludwigshafen company is as diverse and varied as the much sought-after raw material itself. Because oil is not the same everywhere, and each well produces a different type of black gold. Crude oil quality extends from viscid, almost tarry heavy oils to very light, tea-colored variants. And in each case, specially selected oilfield chemicals are used from the drilling to the production stage: the drill head has to be cooled and lubricated, the cuttings dispersed and flushed upwards; the technical process is optimized by additives to the drill flushing fluid circulating in the closed system. Other chemicals prevent the surrounding rock formations from swelling, which could otherwise trap the drill or even cause it to snap.

But drilling alone is not the whole story. The boreholes have to be stabilized as far as the oil-bearing stratum with a circular jacket of concrete. BASF additives are used to control the flowability and setting time of the concrete, allowing it to be ideally adjusted to the prevailing conditions. And even when the borehole has finally advanced as far as the deposit, the engineers are often called upon to provide ingenious solutions. Because oil doesn’t just lie around in underground lakes waiting to be pumped to the surface. Rather, it is enclosed in porous rock formations that only grudgingly yield up their riches. To promote the flow of oil, the tiny pores in the limestone are widened with the aid of hydrochloric acid. Unfortunately, this attacks not only the limestone but also the valuable oil production facilities – so corrosion inhibitors from BASF are used to protect the sensitive equipment by forming a thin protective film on the metal.

To prevent the widened pores from closing again under the weight of the rock formations bearing down on them, special support materials called proppants are required. These include special sands produced by the US company Engelhard recently acquired by BASF. The special sand can be pumped like a liquid around the borehole into the pores that have been created, where it produces a maximum of hollow spaces through which the oil can flow from the deposit to the tubing.

The inherent pressure within the deposit rapidly decreases, but is usually maintained by forcing water into the deposit through injection boreholes sunk at the edge of the oilfield. The water then mixes with the extracted crude oil – a water content of up to 95 percent is not unusual. This is where the customized demulsifiers come in, special surfactants from BASF which greatly accelerate the separation of oil and water. “Demulsifiers are among the most important products in our portfolio, and account for about 40 percent of all oilfield chemicals”, explains Brodt. “And this is the case even though as little as 10 to 15 grams are sufficient to separate a metric ton of oil-water mixture.”

BASF oilfield chemicals, specially developed to be environmentally friendly, therefore contribute in many ways to utilizing more intensively the available crude oil reserves. “And this is still the best way of gaining valuable time in our search for alternatives to crude oil as an energy source”, comments Dr. Klaus Picard, Managing Director of the Association of the German Petroleum Industry. “Because every percent by which we can increase the yield from existing deposits meets a whole year’s global consumption requirements.”

The Prospects

The thirst for energy of newly industrialized countries like China or India is increasingly widening the gap between demand and newly available oil resources. Whether utilizing existing resources more efficiently or tapping into difficult deposits: in both cases engineers are greatly dependent on advanced oilfield chemicals of customized composition.

BASF acts as a feedstocks supplier for internationally operating service companies whose experts prepare the required finished formulations for the major oil companies directly at the borehole. The global market for oilfield chemicals has now reached a volume of around $4 billion with an estimated annual growth of 5 percent. Through the integration of the US company Engelhard and the Construction Chemicals division of Degussa, BASF increased its know-how relating to special sands, concreting additives and polymers for drill flushing fluids.

The Info Box

Oil – how green waste was transformed into black gold and how it is extracted from the ground today Especially during the warm periods of the earth’s history, heavy algae growth in shallow seas and lakes created vast amounts of organic waste. Some of it became enclosed in the earth’s crust and, in the absence of oxygen and exposed to high pressure, was converted into crude oil over millions of years. But only the deposits that have collected in underground reservoirs are commercially viable.

The main steps of oil production

Exploration: Before drilling operations can commence, nature has made it necessary to conduct an often protracted search for promising deposits. Today’s oil prospectors now use leading-edge technologies: information about the position of oil reserves provided by satellite pictures, measurements of subtle differences in the earth’s magnetic and gravitational field and above all, seismic techniques based on interpreting the changes caused by oil deposits in artificially induced shock waves. Electronic “noses” sniff out the tiniest traces of hydrocarbons on the surface. Only when the geologists have precisely located the oilfield can the drilling teams get to work, culminating in the laying of a cemented pipeline between the oil stratum and the ground surface.

Production: Once this access has been established, the often decades-long production phase begin. In the primary phase, up to 10 to 20 percent of the oil is raised to the surface by the inherent pressure of the deposit and by simple pumping technology. In the secondary phase, the necessary pressure is maintained by injecting water under pressure in order to flood out as much oil as possible from the reservoir. In the tertiary phase of oil production, demanding techniques such as injecting hot steam also make it possible to access the oil located deep inside the rock pores – but at least half of the deposits remains in the ground forever.

Contact Information

Dr. Melanie Urtel

BASF

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