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. Introduction Sand production is a major problem in many oil and gas reservoirs worldwide. It can drastically reduce production rates, damage downhole/subsea equipment and surface facilities, thus increasing the risk of well failure. The 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. The potential of sand production is dependent on various factors including in-situ stresses, pore pressure, formation properties, depletion, water-cut etc. If the strength of reservoir rock is low, it will require sand control. On the other hand, high strength rock is not expected to sand and therefore, does not require sand control. Reservoirs with rock strength from moderate to intermediate will benefit most from a sanding prediction study. The completion and operational decisions to prevent or control sanding need to be taken on a well to well basis by considering the individual characteristics of each well. The well characteristics include inclination and orientation in the in-situ stress field and formation strength.

Khafji offshore field, located in the Arabian Gulf, contains an unconsolidated sand reservoir subdivided into two, upper and lower reservoirs. Upper sandstone reservoir has relatively low reservoir pressure utilizing gas lift to help wells achieve production target rate. The main obstacle in upper reservoir is water encroachment due to unfavorably high-water mobility compared to oil; which presents a reservoir management challenge in the form of curbing water production linked to relatively high-permeability sandstone reservoir. In upper reservoir, water encroachment is dominated by active edge-water drive and it has irregular water-front movement because of the presence of high permeability streaks.Excessive water production from the high permeability upper sandstone reservoirs causes major economic, operational, and environmental problems during oilfield operations. Water production can also cause secondary problems such as sand production, corrosion, emulsion, and scale formation. Although the reservoir has been on production more than 50 years, water sources are still considered to be a mystery. Many different concepts and scenarios have been considered such as channeling behind the casing, highly conductive faults, channeling through the high-permeability zones and high-permeability streaks, which accelerated water production. As a result of this issue, water breakthrough at crested wells in an edge-water driven upper reservoir and water production has increased. Inflow Control Devices (ICD) completion has been installed in upper reservoir wells to overcome water production challenges. Low reservoir pressure is a major challenge for upper reservoir wells ICD completion design. During the course of this paper, Khafji field water encroachment study results have been discussed to show the latest water front movement expected scenario. In addition, ICD-completed wells performance was analyzed and compared to cemented perforated liner completion wells (Non-ICD completion) offset wells in upper reservoir. The parameters that were used during the ICD-completion design to overcome the main field challenges were highlighted. ICD completed wells showed positive performance results in water production control and higher oil production rate.