Elastic Modulus and Unconfined Compressive Strength Study of Middle Cretaceous Formations, Dhifriya Field Middle Iraq

Abstract

Dynamic elastic properties are calculated from the measurements of elastic compressional and shear velocities with corrected bulk density in Middle Cretaceous Formation, Dhifriya Middle Iraq. Static elastic properties were calculated from the correlation equations with dynamic elastic properties. The differences between dynamic and static elastic properties are caused by the presence of microfractur es. From the dynamic young modulus and total porosity which was derived from Neutron –Density logs; the Unconfined Compressive rock Strength (UCS) was calculated. Compressional velocity was derived from sonic data and then shears velocity was estimated from Vp using Green Castagna equations. Techlog software were used to calc ulate static and dynamic elastic properties with rocks strength UCS based on well log data taken from two wells in Dhifriya field Dh -1, Dh-2. The results show that the rocks with high porosity and low density have low rock resistance for drilling and break ing (low UCS), while the rocks with high density and low porosity have high resistance for drilling and breaking(high UCS).