In the oil and gas industry, velocity modelling can help you better understand why the gas flow pattern in wells differs from those predicted by conventional modeling techniques. With this understanding, you can make well performance more predictable and improve your production rates by better controlling gas influx into oil wells and by preventing water influx into gas wells. Here’s what you need to know about velocity modelling in the oil and gas industry—and why it could lead to improved well performance as well as lower costs of operation.
What is velocity modelling?
Velocity modelling is a technique used to estimate how long it will take for energy sources to get from one location to another. In order to better understand velocity modelling, we need to understand how it compares with other methods of measuring fluid flow, such as Darcy’s Law and Eddy’s Law. This can help us determine when we would use one method over another. Understanding each method will also help us analyze which one works best for certain situations. Though there are multiple ways to measure velocity, most are based on solving either an advection or convection equation. We don’t want to confuse you so let’s just compare these two equations with examples for clarity. These techniques work by considering variations in fluid viscosity and density – both things that affect velocity estimates due to Newton’s second law of motion (F=ma).
How velocity models are developed
There are many possible ways to develop a velocity model. The method you choose should depend on several factors, including the characteristics of your reservoir, your technical expertise, available tools, cost constraints and others. Your goal should be to choose a method that yields a model that’s both accurate enough for use in production operations (saving costs) while still sufficiently accurate for evaluation purposes (helping you identify drilling locations). One way of achieving both goals is through dynamic simulations using geostatistical techniques. There are at least three common methods that can help you build an effective velocity model. In all cases, these methods begin with velocities measured in wells or calculated based on pressures and other well-logging data. That data is then analyzed statistically to build one or more models capable of producing reasonably good predictions of velocities at new locations throughout a field. Because these models rely heavily on statistical analysis, they tend to be relatively easy and inexpensive to construct—and they typically work best when used as part of an iterative process involving some degree of manual input from subject matter experts.
Why velocity models matter to engineers
One of our favorite things about energy reservoir engineering is that there are always new challenges to overcome. That’s why we love using advanced solutions, such as Petrel’s Velocity Modeling capabilities, to help engineers make sense of a complex subsurface. Whether you’re targeting unconventional plays or planning a multistage operation, Petrel can provide clear insight into your reservoir. We want to help you understand how your drilling plan stacks up against resources available from well logs, seismic data, and other input sources. Read on to learn more about how Petrel helps with one of today’s most common challenges: defining targets for future wells.