Role and Contribution of Pressure Regime Evaluation in Well Planning and Formation Evaluation Process, Zeit Bay Field - Gulf of Suez, Egypt

Summary: The study aims to construct a simple and effective pressure regime model for Zeit Bay Field which can assist the well planner to predict the pore pressure for the upcoming wells to be drill in the field. It aims also to find out the relationship between the constructed pressure regime model and the geological setting of the field. Introduction: An adequate prediction of the Pore Pressure and better understanding for the Pressure Regime Model of any area are very important prior drilling any well. They can play a vital role at several stages of Exploration and Development Process. ? In Exploration Phase, they help in:-Providing calibration to Basin Modeling.Mapping Hydrocarbon Migration Pathways.Assessing the "Seal" effectiveness.Analyzing the "Trap" configuration and geometry for a Prospective Basin. In Development Phase, they help in:-Anticipating the location and potential magnitude of possible formation pressure problems.Providing suitable casing and mud program designs leading to Minimize Drilling Cost.Avoiding Environmental Pollution, Loss of Reserve, Loss of Human Life...etc). But it is worth mentioning that, it is very important to recognize and evaluate any changes in the Estimated Pore Pressure data during the drilling of a new well. The updated information can be used to implement the new well proposal. General Outline about Zeit Bay Field: Zeit Bay field is an oil field located in the southwestern offshore part of the Gulf of Suez, some 65 km north of Hurghada and 85 km south of Ras Gharib. The field extends to the onshore and is combined with General Petroleum Company's Bahar North -East field. (fig.1) The field was discovered in June 1981 through the drilling of the Exploratory well "QQ 89-1" which was drilled in the crestal part of the structure and considered as gas producer well. In October, 1981 another well "QQ 89-2" was drilled 2 km south and down dip from well QQ 89-1. This well recorded the underlying oil-leg with an oil water contact at 4850 feet sub-sea. The commercial field production has been started in December 1983 with average daily rate 20000 BOPD. Structurally, Zeit Bay field is interpreted as a NW-SEbasement relief like anticline feature. This anticlinal feature is however, dissected into several fault block panels by two main fault systems. A set of NW-SE trending faults affecting the western and eastern flanks. Another set of W-NW/E-SE trending fault system affecting the northeast flank. Some of these faults die out at/ or near top Belayim except the extreme bounding faults. In addition to the northeast and southwest blocks there are a parallel narrow elongated rectangular high blocks down stepping away from the above triangular horst blocks. (fig.2)