Petroleum Engineering: Flow, Reservoir, and Wellbore

Name: Petroleum Engineering: Flow, Reservoir, and Wellbore
Author: KnowledgeCity

Learn about well testing and analysis

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Course: On-Demand

To understand the radial flow in the reservoirs, it's necessary to understand that this is one of four geometric classifications of the flows in the deposits. These depend on the way in which the producer interval is terminated on the elements that limit the porous medium and on the heterogeneities present. This includes failures, anisotropy, and coinage, among others. The types of flow according to their geometry are linear, spherical, elliptical, and radial. Linear flow consists of parallel flow vectors. The linear flow is identified by a straight-line trend with a positive slope of 1/2 on the graph of the derivative and occurs when the flow is uniform. This system is presented in hydraulically fractured wells, horizontal wells, and long deposits. Since the current lines converge to a plane, the parameters associated with the linear flow are the permeability of the formation in the direction of the flow lines and the area of normal flow to the current lines. Spherical flow occurs when the current lines converge to a point. This system occurs in wells that have been partially completed or in partially penetrated formations. In the case of partial completion or partial penetration near the top or the base of the formation, the nearest impermeable layer imposes a hemispheric flow. Both spherical and hemispheric flow are seen in the curve of the derivative as a negative slope with a value of 1/2. Once the permeability of the radial flow is determined, it can be used as horizontal permeability to determine vertical permeability. This last one is important to predict gas or water conification. Elliptical flow, also called biradial flow, occurs in horizontal wells or in hydraulically fractured wells exhibiting a positive slope of 1/3. Hydraulically fractured wells with low conductivity fractures can exhibit additional bilinear flow to the linear flow. This system occurs due to a pressure drop in the fracture that results in parallel current lines in the fracture while there are normal flow lines in the formation. The term bilinear refers to two simultaneous linear flows that occur in normal directions. Finally, we have the radial flow, which is the most important flow system in the interpretation of pressure tests. This is recognized by a constant extension or flat train in the derivative. Radial flow geometry is described as streamlines that converge towards a circular cylinder or well. In wells completed in the entire perforated interval, the cylinder can represent the portion of the well intercepting the entire formation. In partially penetrated formations, the radial flow may be restricted at early times to only a section of the formation interval where the flow is directed towards the well. When the well is stimulated or in horizontal wells, the effective radius for radial flow could be lengthened. Whenever there is radial flow, permeability and damage values can be estimated. When radial flow takes late times, reservoir pressure can be estimated in pressure restoration tests. This flow pattern occurs in wells located in deposits where the effects of the edges are not yet felt, so they seem to have an infinite extension. The density of the current lines per unit area increases when approaching the well. This causes a logarithmic distribution of pressure versus distance from the well. In extreme cases, the convergence of the current lines will cause the flow to become turbulent, causing a drop in extra pressure, apparently, as an additional factor of damage. In the longterm, the approximation of this flow pattern is logarithmic.

Essential Provider : KnowledgeCity 5 Lessons · 12m in Arabic, English

Course Description

Well testing is a valuable tool for reservoir engineers for evaluating well performance and diagnosing characteristics. In this course, Flow, Reservoir, & Wellbore, you will learn about the various tests used to diagnose unexpected well or reservoir behavior. We will discuss measuring the damage factor, which occurs during drilling and completion, as well as measuring well delivery capacity. We will also explore the flow behavior of a well, deposit characteristics, and production mechanisms.

In this course, you will learn how to measure damage factor with positive and negative values. You will also learn about using productivity tests to measure identity and amount of fluids inside a well. We will explore characteristics such as pressure of the reservoir, viscosity of the fluids, and porosity and permeability of the deposit. By the end of this course, you will understand the four geometric classifications of flows in the deposits–linear, spherical, elliptical, and radial.

What You'll Learn

Differentiate between the four geometric classifications of flows in deposits: linear, spherical, elliptical, and radial
Determine well delivery capacity using productivity and well tests
Measure the damage factor (skin) with both positive and negative values as it occurs during drilling and completion
Analyze deposit characteristics such as reservoir pressure, fluid viscosity, porosity, and permeability
Evaluate wellbore flow performance and well deliverability
Use productivity tests to identify the type and amount of fluids inside a well

Key Takeaways

Well testing is a tool reservoir engineers use to evaluate well performance and diagnose unexpected well or reservoir behavior.
The damage factor occurs during drilling and completion and can be measured with positive and negative values.
Productivity tests are used to measure the identity and amount of fluids inside a well.
Flows in deposits fall into four geometric classifications: linear, spherical, elliptical, and radial.
Reservoir and fluid characteristics studied include reservoir pressure, fluid viscosity, porosity, and permeability of the deposit.

Frequently Asked Questions

What will I learn in this Flow, Reservoir, and Wellbore course?

You will learn about the various tests used to diagnose unexpected well or reservoir behavior, how to measure the damage factor and well delivery capacity, and how to differentiate between the four geometric classifications of flows in deposits: linear, spherical, elliptical, and radial.

Who is this course for?

It is aimed at reservoir engineers, for whom well testing is a valuable tool for evaluating well performance and diagnosing well characteristics.

What topics does the course cover?

The course covers radial flow in oil and gas wells, wellbore flow performance, well deliverability, damage and skin, and testing and analysis. It also explores flow behavior, deposit characteristics, and production mechanisms.

What deposit characteristics does the course explore?

The course explores characteristics such as the pressure of the reservoir, the viscosity of the fluids, and the porosity and permeability of the deposit.

What skills does this course help build?

It helps build skills in hydraulic analysis, hydraulic testing, petroleum engineering, well completion (oil and gas), and well testing.