High Pressure Natural Gas Compression for Enhanced Oil Recovery in Unconventional Reservoirs

Overview

EOR in unconventional reservoirs is a fairly new concept and we have been partnering with a number of top Eagle Ford shale producers to ensure successful results. The use of high pressure natural gas allows operators to take advantage of an affordable and easy-to-access resource that is typically available on-site or from nearby pipelines. Experience and knowledge are crucial in the design of the required surface equipment due to the many complexities. Exterran has succeeded in the application of this compression process and we have the background to provide properly engineered, designed-for-purpose equipment to ensure a successful project. Please click here to download our white paper for more detailed information.

Complete Confidence in Exterran Packages:

  • Exterran’s 60 years of experience and unsurpassed expertise as the global compression leader assures high-performing packages
  • Experience providing packages for leading Eagle Ford producers
  • Exterran engineering ensures consistent quality, predictable performance, simple operation and easy maintenance
  • Ability to engineer and manufacture a comprehensive solution to meet customer needs
  • Compact skid designs and transportation-considerate packaging practices reduce permitting requirements and associated trucking costs
  • Engineering and operations experts are available to assist with configuration decisions and technical support

Key Benefits

  • Delivery in 35 - 40 weeks (subject to engine delivery times and prior sale)
  • Expedited production drawings available for faster planning
  • Single well or multi well designs available along with full pad well designs
  • Robust skid design and commitment to service help bring operations online quickly
  • Cost-effective maintenance
  • Installation and commissioning of the units to facilitate and speed startup
  • Industry-leading delivery to speed startup

How it Works

Exterran’s high pressure natural gas compression solution for EOR focuses on the use of compressed natural gas for miscible gas injection in unconventional reservoirs.

At the subsurface level, it is unclear the exact processes occurring in these tight formations, but a general understanding can be provided by classical equilibrium behavior. First-contact miscibility implies a critical condition of the fluid mixture of the oil and injected gas. The goal of miscible flooding is the development of critical conditions in the reservoir and continued operation above this point. At a unique oil-to-gas ratio in the reservoir, there may exist a pressure at which the mixture is a critical fluid. The classical laboratory EOR swelling test is a measurement to determine the critical point pressure and oil-to-gas ratio. Swelling tests rigorously represent miscible gas injection processes for first-contact miscibility. Critical or near-critical fluids in unconventional shales are among the better producers since they have both desirable product (oil) and good drive mechanisms (gas).

A block diagram of the surface process can be seen in Figure 1 below.

For locations where there is no access to lean, fractionated natural gas, produced gas from the well can be taken off the sales line after processing (dehydration, compression, etc.), and routed to a high-pressure compressor. Several wells can also be tied into this system. Although gas lift is shown, it is not necessarily needed in injection wells, but it is typically needed in offset wells. Having gas lift lines in place makes the installation of compression for EOR more cost-effective, as the required supply lines would already be in place.