Definition of Soft SandDefinition of Soft SandDefinition of Soft SandDefinition of Soft Sand Low unconfined compressive strength Low unconfined compressive strength

(UCS).(UCS). Low Young’s modulus (E).Low Young’s modulus (E). Poro-plastic compressive behavior (low Poro-plastic compressive behavior (low

cohesion).cohesion). Poor core integrity, core wash-out during lab Poor core integrity, core wash-out during lab

teststests Sand production and wellbore stability Sand production and wellbore stability

problems.problems. Stress dependent porosity and permeability.Stress dependent porosity and permeability.

Low unconfined compressive strength Low unconfined compressive strength (UCS).(UCS).

Low Young’s modulus (E).Low Young’s modulus (E). Poro-plastic compressive behavior (low Poro-plastic compressive behavior (low

cohesion).cohesion). Poor core integrity, core wash-out during lab Poor core integrity, core wash-out during lab

teststests Sand production and wellbore stability Sand production and wellbore stability

problems.problems. Stress dependent porosity and permeability.Stress dependent porosity and permeability.

Formation Failure in Soft Formation Failure in Soft SandSand

Formation Failure in Soft Formation Failure in Soft SandSand

Cavity Collapse.Cavity Collapse. Backflow.Backflow. Crossflow.Crossflow. Water Hammer Effects.Water Hammer Effects. Injectivity Decline due to Sand-Injectivity Decline due to Sand-

Filled Perforations.Filled Perforations.

Cavity Collapse.Cavity Collapse. Backflow.Backflow. Crossflow.Crossflow. Water Hammer Effects.Water Hammer Effects. Injectivity Decline due to Sand-Injectivity Decline due to Sand-

Filled Perforations.Filled Perforations.

Design Criteria for Soft Design Criteria for Soft SandSand

Design Criteria for Soft Design Criteria for Soft SandSand

Pressure Charged Wellbore Area.Pressure Charged Wellbore Area. Solid Flow in Two Directions.Solid Flow in Two Directions.

Pressure Charged Wellbore Area.Pressure Charged Wellbore Area. Solid Flow in Two Directions.Solid Flow in Two Directions.

Completion Methods for Water Injection Completion Methods for Water Injection

WellsWells Completion Methods for Water Injection Completion Methods for Water Injection

WellsWells Very weak consolidated formation from top to bottom.Very weak consolidated formation from top to bottom.

– Gravel pack.Gravel pack.– Open hole completion with a pre-packed screen if zone Open hole completion with a pre-packed screen if zone

isolation is not required and there is a narrow grain size isolation is not required and there is a narrow grain size distributiondistribution..

Weakly consolidated formation, low injection pressure.Weakly consolidated formation, low injection pressure.– Selective perforation with a propped hydraulic fractureSelective perforation with a propped hydraulic fracture– Selective perforation with a frac pack, without a screen Selective perforation with a frac pack, without a screen

Weakly consolidated formation, high injection pressure.Weakly consolidated formation, high injection pressure.– Selective perforation with a high injection pressure. Injectivity Selective perforation with a high injection pressure. Injectivity

enhanced by thermal crackingenhanced by thermal cracking..

Consolidated formation with limited weak zones.Consolidated formation with limited weak zones.– Selective perforation Selective perforation

Uniformly strong formation.Uniformly strong formation.– Open hole completion, no screenOpen hole completion, no screen– Perforated completion with or without additional stimulationPerforated completion with or without additional stimulation

Very weak consolidated formation from top to bottom.Very weak consolidated formation from top to bottom.– Gravel pack.Gravel pack.– Open hole completion with a pre-packed screen if zone Open hole completion with a pre-packed screen if zone

isolation is not required and there is a narrow grain size isolation is not required and there is a narrow grain size distributiondistribution..

Weakly consolidated formation, low injection pressure.Weakly consolidated formation, low injection pressure.– Selective perforation with a propped hydraulic fractureSelective perforation with a propped hydraulic fracture– Selective perforation with a frac pack, without a screen Selective perforation with a frac pack, without a screen

Weakly consolidated formation, high injection pressure.Weakly consolidated formation, high injection pressure.– Selective perforation with a high injection pressure. Injectivity Selective perforation with a high injection pressure. Injectivity

enhanced by thermal crackingenhanced by thermal cracking..

Consolidated formation with limited weak zones.Consolidated formation with limited weak zones.– Selective perforation Selective perforation

Uniformly strong formation.Uniformly strong formation.– Open hole completion, no screenOpen hole completion, no screen– Perforated completion with or without additional stimulationPerforated completion with or without additional stimulation

Completion Methods for Completion Methods for Water Injection Wells In Water Injection Wells In

Weak FormationsWeak Formations

Completion Methods for Completion Methods for Water Injection Wells In Water Injection Wells In

Weak FormationsWeak Formations Gravel/Frac Packing.Gravel/Frac Packing. Open hole with a screen or a pre-Open hole with a screen or a pre-

packed screen.packed screen. Perforation with a propped hydraulic Perforation with a propped hydraulic

fracture or thermally induced fracture.fracture or thermally induced fracture. Selective perforation.Selective perforation.

Gravel/Frac Packing.Gravel/Frac Packing. Open hole with a screen or a pre-Open hole with a screen or a pre-

packed screen.packed screen. Perforation with a propped hydraulic Perforation with a propped hydraulic

fracture or thermally induced fracture.fracture or thermally induced fracture. Selective perforation.Selective perforation.