Nodal Analysis - Well Inflow Mechanism & Performance

What is well performance and what is Nodal Analysis?

Well performance is the discipline that aims to maximize a well production. It involves the understanding of the well production mechanisms known as the well inflow and the well outflow. The well inflow describes the laws that drive the flow of hydrocarbons from the reservoir to the bottom of the well. The well outflow describes the laws that drive the flow of hydrocarbons from the bottom of the well to the surface. Both mechanisms are part of what is called the nodal analysis. Nodal analysis studies the evolution of the pressure between two system nodes. Applied to well production, the system usually starts with a node in the reservoir and finishes with a node in the surface tank or production separator. Fluid movement from one node to the other will trigger an evolution of the hydrostatic pressure and of the frictions (or pressure losses). The change of these two pressures (hydrostatic & frictions) will be equal to the difference in pressure between both system nodes. By measuring the pressure at a specific node (for instance, using a pressure gauge installed in the production separator) and using nodal analysis, the pressure in another node of the system can then be calculated and used to decide on specific action aiming at increasing the well production.

Well production mechanisms are one of the most important things to understand when working at optimizing a well. Whether a well is in natural flow or if it uses artificial lift, mastering the concepts of inflow and outflow will allow us to understand any well behaviour and optimize it.

In this class, reservoir engineering, petroleum engineering and well performance will be put together to give a strong and global understanding of the inflow mechanism. Students will learn all the key concepts to master how hydrocarbons flow from the reservoir to the bottom of the well.

The course covers all aspects that govern the well productivity index. All parameters of the productivity index formula will be discussed. Their evolution with reservoir production and their impact on the well productivity will be explained.

To do that, the course begins by presenting different productivity index models and formulas. Then, characteristics of reservoir rock (porosity, saturation, permeability…) are presented to see how they impact the well productivity.

The next section of the training deals with PVT and fluid properties (solution GOR, bubble point pressure, viscosity…). Here again, the impact on the well productivity is reviewed.

The last part of the curriculum focuses on the other terms of the productivity index (like the drainage radius or the skin) and presents deliverability curves (aka IPR curves).

Practical topics are discussed along the course, like the risk of water or gas conning so that students can better react when confronted with these situations.

Combined with the course Nodal Analysis – Well Outflow, students should be able to apply this knowledge in practical situations, like determining if a well is a good candidate for a matrix stimulation or for a conversion from gas lift to ESP.

This course offers a comprehensive learning experience with clear instructions. Enroll today!

Objectives:

This course connects reservoir engineering to well performance and petroleum engineering. Participants will learn about reservoir and fluid properties and get a deep understanding of the inflow mechanism. Taken together with Nodal Analysis – Well Outflow, it will teach what a senior petroleum engineer should know about nodal analysis, well performance, and well production.

Curriculum:

• Productivity index formula, its units and different expressions

• Productivity index in biphasic production
• Gas productivity index and well inflow formula
• Characteristics of reservoir rock:
  • Porosity
  • Saturation
  • Permeability (absolute, effective and relative)
  • Oil-water relative permeability
  • Oil wet vs. water wet rock – Effect on relative permeability
  • Oil-gas relative permeability
  • 3 phase relative permeability
  • Anisotropy
  • All you need to know about coning. When is it a risk?
• PVT and fluid properties:
  • Hydrocarbon phase diagram
  • Fluid models (black oil, volatile oil, wet gas, dry gas, retrograde condensate)
  • PVT experiments (flash and differential liberation) and fluid sampling
  • Bubble point pressure
  • Solution GOR (Rs)
  • Viscosity and its evolution vs. pressure and temperature
  • Formation volume factor
• Drainage & well radius, reservoir thickness
• The difference between drainage and investigation radius
• Skin (geometrical, completion, damage…)
• Deliverability curve (linear, Vogel and composite)
• Free petroleum toolbox
  

Designed for:

• Production, Petroleum or Well Performance Engineers to maximize their well production
• Reservoir engineers to link reservoir engineering with well production
• Field Production Personnel to understand the criticality of data
• Completion or Surface Facilities Engineers to understand what they can do to help maximizing well production

Pre-requisites:

• Basic knowledge on well architecture
• Awareness on the oilfield terms