Geomechanical Characterization of a Sandstone Reservoir in Middle East— Analysis of Sanding Prediction and Completion Strategy

摘要

Sanding problems are often observed in fields after a period of relatively smooth operation. These occurrences usually coincide with an increase in depletion, water cut, or changes in the artificial lift mechanism used to produce the hydrocarbon. Sanding is detrimental to optimum field development and therefore, information about the possible advent and extent of sanding will be helpful in planning for completions and facilities. The study presented in this paper characterizes the geomechanic behavior of a field in which sanding problems are expected after depletion, increase in water cut, and installation of ESPs to optimize production. To accomplish this task, a 3D full field model was created. First, several 1D Mechanical Earth Models (MEMs) were developed. These 1D MEMs were calibrated using drilling data, laboratory measurements, well tests and other field measurements. The calibrated rock mechanical properties from the 1D MEMs were distributed in the 3D model using Gaussian sequential simulation technique. The populated 3D model was then used to perform a coupled geomechanical simulation to evaluate the changes in stress with time and production. The rock mechanical properties and stresses needed to perform sanding analysis were sampled along the well trajectories from the 3D model. Sand production prediction analysis was subsequently undertaken using a field proven sanding prediction model that accounts for scale effects associated with different perforation size and sand grain diameter, and plasticity effects that modify the strength behavior of sands surrounding open holes and perforations during drawdown and production. The sanding tendency predicted from sanding analysis was corroborated with field observations. This was also used to calibrate the 3D model and formulate a completion strategy to minimize sand production for the life of the field. The completion strategy optimizes the production using ESPs while minimizing sand production.