They share information, but ultimately only one site will be crowned the "golden spike" location for the Anthropocene: the place on Earth where a line in the rock, mud or ice exemplifies the unique markers of the age of humans.Įvery geological period has a golden spike location that allows scientists to pinpoint when the period began by identifying a specific layer in rock, mud or ice and assigning a date to that layer.įor example, there is a line of pollen and dust in a specific ice core from Antarctica that is the official reference point for the beginning of the Holocene epoch, which commenced when the last ice age ended about 12 thousand years ago. Teams are studying 11 locations on five continents, looking for a place where rock, mud or ice perfectly capture the global impact of humans.Īs is often the case in science, the teams are both collaborating and competing. ![]() Those are the questions that geologists are pursuing with increasing urgency at sites around the world. Humans have changed the Earth in such profound ways that scientists say we have entered a new geological period: the Anthropocene Epoch.īut when did the new epoch officially begin? And how, exactly, should it be defined? Justin Wilkinson, Texas State U., Jacobs Contract at NASA-JSC/NASA The Flinders Reef area of the Great Barrier Reef is one of 11 sites around the world where scientists are looking for decisive geological evidence of a new epoch called the anthropocene. The pad mud should exhibit controllable fluid-loss characteristics to minimize filter-cake buildup across permeable sands.A portion of Australia's Great Barrier Reef photographed from the International Space Station. A comparison of proposed casing running speed with surge-pressure tolerances.Transport efficiencies and annular shear rates at different flow rates.The equivalent circulating density (ECD) on the bottom and the annular cuttings concentration at different ROPs and flow rates.The maximum recommended rate of penetration (ROP) at various flow rates and cuttings concentrations.Modeling-anticipated hole conditions allow the drilling-fluids engineer to predict the effects of interdependent parameters such as: A properly designed pad mud helps to ensure that the wellbore will remain stable while surge pressures are minimized. Īccurate modeling helps when formulating an optimal pad mud for each well. This type of system has been used for the riserless portion in several deepwater operations. The fluid should be virtually solids-free to help avoid settling in the tanks. The ideal fluid is thin enough to be transported by a standard centrifugal pump, yet retains the desired rheological properties when blended with seawater.įor remote locations that do not have continuous workboat support, using a ballast-storable fluid system helps ensure that the operator has access to the required volume of drilling fluid during inclement weather. Using a specialized, polymer-free base fluid facilitates efficient pumpoff from supply boats. A three-inlet, high-performance eductor is used to blend riserless drilling fluids, which allows a third stream of CaCl 2 or an alternate inhibitive brine to be mixed with standard seawater and base-fluid streams. Typically, drilling fluid must be mixed and treated at flow rates of up to 1,000 U.S. Precisely engineered “pad muds” for maintaining wellbore stability while running casing. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |