Tubing specifications selection and its effect on the results of hydraulic fracturing treatment in oil formations

Abstract

Equipment specification, data collection and design process are critical factors for any hydraulic fracturing treatment success. This paper investigates tubing specifications selection and its effect on the results of hydraulic fracturing treatment in oil formations. Simulations were carried out on well E-45 owned by National Oil Corporation (NOC) of Libya using two main tools - Pumping Diagnostic Analysis Toolkit (PDAT) and Halliburton proprietary software package (FracPro) for analysing Mini-Frac pumping data. The initial modelling results using 3.5 inch tubing were compared with the experimental results obtained from the actual hydraulic fracturing tests carried out at the E45 by Halliburton as a sub-contractor for NOC. The simulation results showed good agreement with the experiments, validating the model. The model was then extended to explore alternate tubing diameters. This was implemented by introducing the relationship between the tub friction pressures and pumping rate (Friction Pressure vs. Pumping Rate) with the mentioned tube sizes. The results showed that in high stress rock formations, it is worthwhile to minimise the pipe friction by using higher tubing grade (4.5 inches) and burst pressure. A bigger tubing inner diameter can increase the allowable surface pumping rate and pressure