Fathi Boukadi

Field Application of Phenol Formaldehyde Gel in Oil Reservoir Matrix for Water Shut-off Purposes

Abstract A few wells from a major western India on-shore oil field are either on the verge of being shut in or have already been abandoned due to excessive water-cut (WCT) levels. Low injectivity and extreme temperatures (149°C) make it difficult for water shut-off by conventional polymer gel injection. A water-thin monomer-based in situ gelation system has been developed and successfully tried in one of the wells that ceased production due to 100% WCT. The average production of 420 barrel of oil per day (BOPD) with less than 1% WCT, in the first year of production back in 1996, has declined to less than 8 BOPD (with 98% WCT) prior to shut-in in year 2002. A rise in the oil-water contact level in combination with a coning effect was diagnosed as a possible cause of the high WCT, which was later controlled by a newly developed gelant treatment. In fact, the average post-treatment production for the first 3 months was nearly 200 BOPD. Thereafter, production gradually stabilized in the neighborhood of 115 BOPD with a WCT of 48%. Cheap chemicals and a fast treatment method have resulted in a payback time span of 5 days and made an additional profit of U.S.

Production scheduling for continuous manufacturing systems with quality constraints

0.6 M. The water shut-off job resulted in an impressive commercial success; technical success, however, was less than satisfactory due to the fact that, in spite of using a water-thin monomeric solution, only 40% of the designed volume could be injected due to low injectivity resulting in an abnormal pressure build-up. In addition to the gel development and treatment experiences, this article describes in detail the results of further lab investigations carried out to identify the possible reasons causing injection failure.

Mathematical Model for Estimating Perforation Penetration Depth

This research is motivated by a real world production scheduling problem in a continuous manufacturing system involving multiple objectives, multiple products and multiple processing lines with various inventory, production and quality constraints. Because of the conflicting objectives, a global optimization approach is considered as not feasible by the plant management. Given a customer demand forecast, two practical heuristic or sequential optimization algorithms are developed to generate daily production schedules for two primary objectives: minimize shipment delays (pull-backward procedure) and minimize average inventory levels (push-forward procedure). A third heuristic algorithm (reduce switch-over procedure) which is based on the current management practice is also developed to serve as a benchmark. A factorial experiment was performed to evaluate the performance of the heuristic procedures and to identify factors that might affect the performance differences among heuristics. Since each heuristic is designed to give priority to one of the three conflicting objectives, none of them is absolutely superior to the other algorithms in all aspects. However, the first two heuristic procedures performed better than the current management practice in shipment delays and average daily inventory. The production schedules generated by the two procedures also satisfy the quality constraints. The experimental results also showed that the performance of the algorithms is significantly affected by product mix, inventory levels, and demand pattern.

Wellbore Path Estimation Using Measurement While Drilling Techniques: A Comparative Study and Suggestions for Improvements

Abstract This article presents a simplified mathematical model based on the energy-work method to estimate the penetration depth in well perforation. The model uses casing and formation properties in the estimation. It uses the initial speed of the bullet and the failure strengths of the materials resisting penetration as model input. An automated computer program was developed to compute the penetration depth in terms of various field parameters. It was found that bullet penetration increases with increasing jetting velocity and decreasing effective bullet surface area, and that the use of explosive-type HMX1 yields higher penetration depth for the same bore size. The results also showed that the productivity ratio becomes much higher for larger borehole diameters and higher explosive speeds. Overall, the study showed that the model can be used to design for optimum penetration depths leading to an optimum productivity ratio.

New correlation to predict CO2 gas saturation and gas front velocity

Abstract The complexity of wells being drilled has increased over the past few years in order to fulfill the worldwide increase in energy demand. The existing drilling technologies make it possible to construct boreholes with different directions. However, the control of paths and trajectories within the operator requirement is a non-obvious task, because of the data transmission time and the space discretization for measurements. This article aims at reviewing the most common techniques of curvature measurements and data transmission. It also compares them by outlining their advantages and weaknesses.

An Empirical Correlation to Relate Estimated Vertical Permeability from a Horizontal-well Test to Actual Vertical Permeability

Compositional reservoir simulation sensitivity runs were performed to develop correlations that can be used to predict CO2 gas saturation and gas front velocity in oil reservoirs. These correlations are accurate (with average error of less than 5%) and are easy to use. The correlations can also be applied to a diverse range of reservoir types with different fluid properties, producing under different flow regimes. Eclipse 300 was used to build the simulation models. The models were later tuned to investigate different CO2 and flue gas injection scenarios. Parameters like reservoir shape, injected gas and original fluid in place properties, injection and production rates and pressures among others have been used to develop these correlations. More than 400 different simulation sensitivity runs have been performed. This study showed that the gas saturation in different locations of a reservoir can be predicted accurately. Also, it has been observed that every point of the gas front is moving at a constant velocity and was time independent. Velocity, however, was variable along the gas front.

Development of a novel chemical water shut-off method for fractured reservoirs: Laboratory development and verification through core flow experiments

Abstract Field data are requisite in order to set up a realistic reservoir model capable of predicting the dynamic field behavior during the development stage of an oilfield. Well testing is considered as one of the most useful methods for obtaining reservoir and wellbore data. Numerous analytical models are utilized in analyzing vertical-well pressure transient tests, however, horizontal-well transient tests analysis has been considered as a more difficult undertaking. In this article, well test data of a horizontal well are simulated for homogeneous isotropic and anisotropic reservoirs. The data are later used in order to develop an empirical correlation that ratifies the vertical reservoir permeability estimated by well testing.