Simulation Study of Drilling Horizontal Wells in One of Iranian Oil Fields

摘要

The objective of this study is to investigate the advantages of drilling horizontal wells on oil recovery improvement. To evaluate the effect of horizontal length, porosity, anisotropy, staggeredline well pattern with gas injection (in the top layer) and water injection (in the bottom layer), different scenarios were studied. This study is focused on simulation of formation-A of a carbonate reservoir which consists of three layers; where horizontal well is going to be drilled in layer-2 of this formation. The average thickness of formation-A is about 167.64 meters (550 feet) and we also have tilted water oil contact in this formation. This field has produced around 146.9 MMBBL until year 2002 for the last 12 years with the Recoverable Reserve of about 237.31 MMBBL. Up to now 40 wells have been drilled in this field. IRAP/RMS software was used to generate geological model. Based on selected reservoir black-oil model, IMEX from CMG is used for simulation task. Sector model used for simulation as we only had one productive horizontal well in the formation (scale-down method). This study confirms simultaneous use of overbalance method and horizontal well in this reservoir in order to: A) Increase production rate up to 3 to 4.5 times by boosting productivity index (PI). B) Communicate a large area leading to a better drainage area. C) Postpone the water breakthrough by minimizing the draw down pressure.