Use of Amine/PHPA System To Drill High Reactive Shales in the Orito Field inColombia

The use of water based fluids replacing oil based drilling fluids has been increasingly being applied in the Petroleum Industry in order to mainly accomplish environmental legislation.A challenge when using water based drilling fluids in highly reactive shales is to overcome problems such as wellbore instability, torque and drag and environmental requirements. This was the case in the Orito oil field in Colombia.The Orito field is located to the south of the country and has been operated by Petrominerales Colombia Ltd. During years of exploitation, the Orito wells were drilled with oil base muds in order to address wellbore instability problems related to the highly reactive shales of the Villeta formation, which is drilled in the 311 mm (12 ¼