This is a significant and complex topic within reservoir geomechanics. Let me address your questions one by one:

1. Is this possible?

Yes, this is possible. The deformation of a barrier layer between reservoirs in a multi-reservoir field is a real concern in geomechanics. When reservoirs produce at different rates, they generate differential pressure and stress changes in the surrounding rock. If the barrier layer is thin, these stresses can cause:

• Heave or bulging: The barrier might deform upward (or downward) due to the imbalance in vertical stress.
• Shear failure: The differential lateral or shear stresses could exceed the strength of the barrier, potentially compromising its integrity.

The risk of deformation or failure depends on several factors, including:

• The mechanical properties of the barrier layer (elastic modulus, tensile strength, cohesion, and internal friction angle).
• Thickness and heterogeneity of the barrier layer.
• Magnitude and rate of pressure depletion in the reservoirs.
• Distance between the reservoirs.

2. Are there any studies on this topic?

Yes, there are studies and ongoing research in reservoir geomechanics, though the specific focus on thin barrier layers between reservoirs may be niche. Related topics include:

• Compaction-induced subsidence: Studies on subsidence due to reservoir depletion and how it affects overburden and surrounding formations.
• Geomechanical modeling of inter-reservoir barriers: Research on stress redistribution in multilayer reservoirs.
• Wellbore stability and fault reactivation: These often involve barrier layers, especially if the layers are near faults.

Examples of relevant frameworks and methodologies:

• Numerical geomechanical modeling using finite element or finite difference methods (e.g., ANSYS, ABAQUS, or specialized reservoir simulators like CMG or FLAC3D).
• Case studies from oil and gas fields where differential depletion has caused barrier layer deformation or failure.

I can search for specific papers or studies if you'd like.

3. What do you think about the study procedure and its steps?

A well-structured study procedure would involve the following steps:

Step 1: Define the problem

• Identify the reservoirs, their production histories, and the properties of the barrier layer.
• Specify the key risks (e.g., heave deformation, shear failure).

Step 2: Gather data

• Collect reservoir and geomechanical data:Reservoir pressures, production rates, and depletion profiles. Mechanical properties of the barrier (e.g., elastic modulus, strength parameters). Thickness and geometry of the barrier and surrounding formations.

Step 3: Build a geomechanical model

• Create a 3D numerical model of the reservoirs and barrier layer, incorporating:The geometry of the field. Coupled poroelastic or poro-plastic behavior. Appropriate boundary conditions.

Step 4: Simulate production scenarios

• Simulate depletion in the reservoirs with varying production rates.
• Analyze stress redistribution and deformation in the barrier layer.
• Identify conditions that lead to heave, bulging, or shear failure.

Step 5: Evaluate failure risks

• Use failure criteria, such as:Mohr-Coulomb failure for shear deformation. Tensile failure criteria for cracking. Displacement thresholds for significant deformation.

Step 6: Verify and validate

• Compare simulation results with field data if available (e.g., InSAR measurements, well deformation data).

Step 7: Optimize and mitigate

• Develop production strategies to minimize differential stress (e.g., synchronized depletion rates).
• Propose measures to strengthen or stabilize the barrier, if necessary.