Technology Update: Seismic Stimulation: An Eco-Friendly, Effective EOR Alternative

Wooden, Bill (Applied Seismic Research)

OnePetro 

Technology Update

Environmental and economic concerns have led to an increased interest in seismic stimulation as an alternative enhanced oil recovery (EOR) methodology. Seismic stimulation, achievable with the implementation of a single tool, requires significantly lower investments than gas, thermal, and chemical injection methods, while making minimal environmental impact.

Applied Seismic Research (ASR), based in McKinney, Texas, has placed more than 200 of its proprietary seismic stimulation tools in more than 50 locations, including fields in Arkansas, California, Canada, Egypt, Kansas, Mexico, Oklahoma, Oman, and Texas. This article will examine the operation of the tool and highlight the EOR results achieved in a variety of formations.

What is Seismic Stimulation?

Seismic stimulation is the harnessing of low-frequency, high-energy elastic waves to mobilize oil. The method’s origins trace back to the 1950s when it was noticed that natural earthquakes could increase oil production by up to 45%. Attempts in the 1980s to duplicate earthquake effects by the use of surface vibrators above a targeted zone were largely unsuccessful and commercially unviable. Later development of tools that generate subsurface shockwaves proved more promising. ASR received the first patent for its technology in 2000.

A “Greener” EOR Method

In-situ seismic stimulation may be one of the greenest EOR options available. The method doesn’t involve injecting any amount of potentially harmful fluids or chemicals into the earth or dealing with the byproducts created by other EOR methods. In fact, it is implemented in a completely closed wellbore having no hydraulic communication with the formation. It can offer a measure of relief to field operators grappling with issues including managing groundwater contamination from harmful chemicals; dealing with the treatment, transport, and disposal of high volumes of contaminated wastewater; and/or handling the environmental consequences of the intense energy and carbon use occasioned by thermal injections.

How the Tool Works

The seismic stimulation tool (Fig. 1), which has a lifespan of up to 1.5 years and typically requires no maintenance, is powered by a conventional pumping unit and can be installed in abandoned wells at depths from 700 to 10,000 ft. It is relatively easy to transport to wellsites, coming in three preassembled segments in a single crate. The tool is installed into an abandoned wellbore, connected to a rod string and then to a pumping unit. The pumping unit drives movement of three plungers within the tool in unison. The lowest plunger contains a traveling valve to bring in fluids. When the plunger reaches the top of its stroke, it exits the lower barrel to release highly compressed fluids, creating the elastic waves.