WorldOil

Horizontal drilling with liner provides savings

Drilling in the Cretaceous El Abra formation in Mexico’s GOM has proven costly and time consuming because of the difficulty in detecting natural fractures in the limestone formation. This difficulty is caused by the erosion of the formation’s top layer, which was originally reef. Moreover, the differential pressure between the Tertiary layer and El Abra results in several problems, such as lost circulation, stuck pipe, hole cave-ins and bad casing cement jobs. Operator Pemex responded by applying rotary Drilling-With-Liner (DWL) to cut a high-angle hole to the target depth, cement the liner and drill out the following interval horizontally, steering in the reservoir. GEOLOGY Eight fields have been developed in the offshore Faja de Oro or "Golden Lane"-Arrecife Medio, Isla de Lobos, Tiburon, Bagre, Atun, Morsa, Escualo and Marsopa-for a cumulative production of 210 million boe. These fields have produced light crude of 30–40° API from the Middle Cretaceous El Abra limestone.