Chavez E, Marco A. (Baker Hughes Inc) | Garcia, Gonzalo Alberto (Baker Hughes Inc) | Pogoson, Eguaoje James (Baker Hughes Inc) | Li, Lisa (Baker Hughes Inc.) | Cardona, Andres H. (Baker Hughes Inc) | Nelson, Roy N (Baker Hughes Inc)
In developing an encompassing well completion design, an integrated, comprehensive solution study was under taken for the Lower Tertiary, mainly Wilcox Formation in the Gulf of Mexico. The study included reservoir characterization, optimized hydraulic 3D fracture design and modeling, nodal analysis and production forecasting and reservoir simulation to determine optimum well completion requirements such as internal tubing diameter, completion tool inner strings and downhole control valve sizes.
Preliminary studies from the Wilcox Formation were taken into consideration. Assuming a 3000-ft. MD gross height for the Wilcox formation, a representative LAS file containing the main curves for this formation was stretched out to have representative curves for the gamma ray, resistivity, neutron porosity, density, sonic delta compressional and values of core permeability.
The pore pressure and stress gradients were defined for each of the zones selected for stimulation. The stress profile was calculated implementing the Gamma Ray Index (GRI) and VShale on a per-foot basis for the zones selected withthe gamma ray curve and the assumed input values for sand and shale.
The mechanical properties were calculated from correlations for Vp and Vs utilizing the Vsh values as defined above, which in turn determined the dynamic values for Young Modulus and Poisson on the same per-foot foundation. Additional calculations were performed to determine the static values of the same characteristics for each of the selected zone depths.
The optimum well completion configuration was determined by evaluating: the fracture design (optimum treatment schedule for each zone) and minimizing pressure losses in the production tubing. Well completion reservoir simulations assisting to estimate the flow velocity during the well life. The production system was designed to not exceed the critical erosion velocity of the downhole equipment.
The study supports re-defining the well completion design requirements (maximum ratings) for ultra-deep water, high pressure and temperature applications.