LIVE SAVING INVENTION WITHOUT PATENT COVERAGE

LIFE SAVING INVENTION WITHOUT PATENT COVERAGE

By: Jum’an

Drilling Fluid is an important part in Oil and Gas drilling. In fact it is the only answer to the question: How to drill a small diameter hole thousands of meters deep, and at the same time cleaning and keeping it open without caving. Drilling Fluid is basically a type of slurry pumped down the hole while drilling, through the drill pipes to flush the drilled cuttings and some other duties, and circulated back through the annulus to the surface. There are similarities in the functions of the human blood and oil well drilling fluid. Blood eliminates waste products of metabolism from the human body. Drilling fluid removes drilling wastes, i.e. drilled cuttings from the hole. Blood helps to cool or warm the human body as drilling fluid helps to cool the drill bit and pipes. Blood circulates round the human body via an artery-vein system of connection and drilling fluid circulates down hole and back to the surface via a drill-string-annulus connection system. The mud pump resembles the heart in the oil well drilling. Human blood as well as drilling fluid is re-useable, both work continually. Blood contains white blood cells that defend the human body against diseases. Drilling fluid contains additives that strengthen the borehole, prevent formation damage and extend the life span of the drilling fluid. Testing a blood sample can detect our health condition. Testing a drilling fluid sample can tell us the safety condition of the well drilled.

Among the main functions of drilling fluid is to provide hydrostatic pressure to prevent formation fluids (gases, salt water) from entering into the well bore. Dissolved gases like Oxygen, Carbon Dioxide (CO2), and Hydrogen Sulfide (H2S) cause serious corrosion problems leading to metal failures. H2S in particular is critical because of its high toxicity and is fatal to workers when they breathe. H2S gas is ruthless and deadly hazards in the oil and gas industry. It is highly toxic, colorless and has the specific odor of rotten eggs. However the sense of smell is not a reliable warning because exposure to H2S gas will quickly numbs the sense of smell. Loss of consciousness can happen within seconds of exposure to a high concentration of this gas. The presence of H2S gas in the drilling fluid indicates that the gas from the formation enters into the well due to insufficient hydrostatic pressure provided by the drilling fluid. This toxic gas can then escape into the air, putting the personnel on the rig at risk. The only positive means of determining the amount of H₂S present is by testing with approved detectors.

The Garrett Gas Train (GGT) is the most widely used portable unit to determine H2S in drilling fluid. The GGT unit consists of a transparent plastic block that contains three interconnected chambers. A carrier gas is used to flow an inert gas through the chambers. The sample is placed in the first chamber and is acidified to release the H₂S gas. A special Draeger tube is used to measure the effluent gas that is evolved from the sample. The dark stain in the Draeger tube indicates that H2S has evolved from the sample. Mud Engineers are familiar to run this testing equipment. The device is named after Robert L. Garrett, who invented it while working at Exxon Production Research in the early 1970.

Robert L. Garrett

Born in 1933, Bob earned his master's degree in chemistry from Texas Tech University (TTU) in 1957. While working at Exxon in the early 1970s, Bob invented this device that would help save lives out in the oil fields – the Garrett Gas Train (GGT) – a reliable quantitative sulfide detector. H2S gas is a problem on drilling rigs, he said. The poisonous vapors could quickly kill employees and cause drill pipe to become brittle and break. An easy test for it didn’t yet exist. "I saw a serious need for a rig-site chemical test to clearly identify when an influx of sulfides came from the formation down hole and into the circulating drilling mud," Garrett said. "No reliable H₂S test existed for rig use at that time – around 1970 – and lab tests available were too inconvenient for rig use." The device quickly detects dangerous and poisonous H2S when drilling oil and gas wells. This method is widely used on rigs and approved by the API and ISO. Garrett said that neither he nor Exxon attempted to obtain patent coverage on the GGT and neither he nor Exxon have ever obtained any royalty for use of the method.

"I looked on the GGT test device/method as a life-saving benefit for our industry – useful to avoid serious situations and hazards around the drilling rig," he said. "The whole industry benefits from safe drilling practices."  Currently Robert L. Garrett runs his company “Garrett Fluid Technology” based in Texas and served as chairman of several API committees.