Mechanical Properties of Unconsolidated Sands and Their Impact on Frac Pack Design in Niger Delta

Frac Pack design is currently a technique used to perform either sand control and stimulation activities or both. Unconsolidated sands with medium to high permeability are usually affected by fines or particles plugging the perforation which causes productivity impairment. Also when frac pack design is not properly installed, the abrasive and erosional effects of sand particles reduce the frac pack efficiency. A pre-information of rock elastic properties, in-situ stress magnitude, strength parameters like UCS are needed for defining the effective propping agent requirement for controlling sand particle production through screens. This study uses information from well logs in delineating zones of interest and lithological description using Gamma Ray log, Resistivity logs for delineating reservoir sands. Sonic logs were used for deriving the rock mechanical parameters and in-situ stress directions. Based on our study carried out some findings were made. The fracture propagation width for stimulation to be effective is a clear function of the Young's modulus of the materials. The impact of sand grains on the propping design consideration is continuous as abrasive and erosional effect on the proppant used can affect the efficiency of the propping system over time. The uniaxial compressive strength value of the formation was found to be approximately 0.01 times the effective tensile strength value for the respective sandstone reservoirs. Unconsolidated sand values were observed to be having values less than 15MPa across the wells in the field of study.