A Construction Method of Complex Fractures in Marine Carbonate Reservoir

Abstract Marine fractured-vuggy carbonate reservoirare important oil and gas reservoirs in China, the Middle East, and North America. In the development process, it is necessary to connect hydraulic fractures and as many karst cavities as possible, which are the main geological components of oil and gas storage. However, the systematic theoretical of how to build complex fractures in fractured-vuggy carbonate reservoirs is scarce. Facing this situation, this paper presents a method that can improve the accuracy of fracturing effect prediction and optimize fracturing process design parameters so as toachieve the purpose of increasing production. It studies the factors that could affect that connection. It is found that the density of natural fractures and cavitiesin the reservoir is the main factor affecting the fracture propagation shape. Meanwhile, the liquid containing cavitiesin the reservoir will attract or repel the fractures. Furthermore, natural fractures will cause the migration of fracture propagation path and hydraulic fractures are easy to continue to expand along the direction of large natural fractures. This methodology could be used in future studies for the marine fracture–vuggy carbonate formation. In addition, the research conclusion could be used to design and evaluate hydraulic fracturing operation.