1.Well conditions
The first step is to evaluate the well conditions, such as the depth, pressure, temperature, deviation, casing size, and fluid type. These factors will determine the type and size of the gun, the shape and size of the charges, the detonation method, and the conveyance mode. For example, deep wells with high pressure and temperature may require high-strength gun carriers, shaped charges with high penetration and low debris, and electric wireline or tubing-conveyed perforating (TCP). Horizontal wells with complex trajectories may need flexible or retrievable gun systems, charges with uniform entry holes and low skin, and coiled tubing or tractor systems.
2.Reservoir characteristics
The second step is to analyze the reservoir characteristics, such as the lithology, porosity, permeability, fluid saturation, and stress regime. These factors will influence the perforation strategy, the number and spacing of the shots, the orientation and phasing of the charges, and the post-perforation treatment. For example, tight or fractured reservoirs may require high-density perforation patterns, charges with large hole size and deep penetration, and perforating underbalanced or with propellants to enhance the fracture initiation and conductivity. Sandstone or carbonate reservoirs may need low-density perforation patterns, charges with small hole size and controlled penetration, and perforating overbalanced or with acid to prevent the formation damage and sand production.
3.Operational objectives
The third step is to define the operational objectives, such as the target production rate, the recovery factor, the well integrity, and the environmental impact. These factors will affect the perforation design, the performance evaluation, the quality control, and the safety measures. For example, high-rate wells may require large flow area and low skin perforations, performance tests with pressure and flow measurements, quality checks with calipers and cameras, and safety precautions with barriers and isolation devices. Low-rate or marginal wells may require small flow area and high skin perforations, performance tests with tracer or spinner surveys, quality checks with gauges and sensors, and safety precautions with plugs and valves.
4.Economic constraints
The final step is to consider the economic constraints, such as the budget, the time, the availability, and the reliability. These factors will influence the perforation selection, the optimization, the execution, and the contingency. For example, low-cost wells may require standard gun systems, simple optimization methods, efficient execution procedures, and minimal contingency plans. High-cost wells may require customized gun systems, advanced optimization methods, rigorous execution procedures, and comprehensive contingency plans.
By following these steps, you can select the best perforating gun system for your well that meets your technical, operational, and economic requirements.
Post time: Jan-27-2024
