Sanding Volume OH

With the Sanding Volume OH form (solids production > Sanding Analysis > Sanding Volume OH) you can calculate the mass of produced sand. When a wellbore is not cased or cemented, sanding occurs due to plasticity of rock surrounding the wellbore. In order to analyze how much sand will be produced, the area which will be plastic (i.e. subject to deformation) and the plastic volume should be calculated first. From this volume, the sand mass can ultimately be calculated using density.

Important  Since sand mass calculation will be provided only for samplings where sanding was detected, the sanding evaluation should be executed and Load Factor logs should have been calculated with the Sanding Evaluation Log form.

To calculate the sand volume and sand mass

Specify Input Data

Area Input

On the Area Input tab you specify the following input data which is used to calculate the plastic area (specify either as constant or as log): Young's Modulus, Internal Friction Coefficient, UCS, Plastic Zone UCS, Borehole Radius and Dilatation.

Mass Input

On the Mass Input tab you specify the following inputs, which are used to calculate the sanding volume and its mass:

Density  Specify the density either as log or as constant.

Drawdown Limit

On the Drawdown Limit tab you define how the drawdown value is applied in the plastic area calculation. If the input drawdown exceeds the plastic strength of the formation, the plastic area cannot be calculated. This tab allows you to control how such cases are handled:

Actual Drawdown  Uses the drawdown values as defined in the selected Production Scenario. This is the default option. If the specified drawdown exceeds the plastic strength at a given depth, the plastic area is not calculated for that sampling.

% of Plastic Strength Allows you to specify the drawdown as a percentage of the formation plastic strength. When this option is selected, the algorithm compares the input drawdown from the Production Scenario with the plastic strength at each sampling. If the original drawdown exceeds the plastic strength, it is automatically limited to the specified percentage of plastic strength for that sampling. For samplings where the original drawdown does not exceed the plastic strength, the original drawdown value is used unchanged. This approach ensures that the plastic area can be calculated where otherwise not possible, while preserving the original drawdown values wherever valid, resulting in a conservative (pessimistic) sanding scenario.

Field Observation Factor  When you use this factor, the calculated mass will be multiplied with this factor. You can use this multiplier in case you want to 'tie' calculated values to field observations without changing input parameters, especially when it is not clear which parameter has the highest impact on the results calculations.

(Re)Calculate  First, to calculate the plastic area, the application executes the algorithm similar to the one in the Elasto-Plasticity module of GMI SFIB software. The result of the calculation is, at every depth sample, the size of the plastic area. Once the plastic area is calculated per every sampling, the thickness of the plastic zone(s) can be calculated. After that the sand volume is calculated using the simple formula: Volume = Thickness * Area. The mass of the sanding volume can subsequently be calculated using the Density log, using the formula: Mass = Volume * Density. Output logs for volume and mass are stored in the JewelExplorer under Well Data > All Logs, under the respective log type.

If you specified multiple Production Scenarios on the Production Scenarios form, the plastic area will be calculated for every scenario and for all samplings where the Load Factor log has a value greater than 1.0.

Show Area  Click this button to visualize the plastic area in the dedicated Plastic Zone Area view. See Plastic Zone Area View for more information.

Show Mass  Click this button to visualize the (cumulative) Sand Volume and Sand Mass logs in the Solids Quantity OH view (this is a dedicated Well View with default settings for sanding quantification) and the cumulative produced sand mass in the Solids Production OH view.