Advanced Produced Water Recycle and Reuse Technology /RO Integrated Unit

The Background

Texas citizens need large volumes of water for agriculture and human use, and the diminishing water supply from the major aquifers supplying water has resulted in a search for additional water resources. Oil and gas development brings significant volumes of water to the surface. In Texas there are currently over 300,000 operating wells producing over 500 million gallons of water a day.

However, the produced water contains salts and minerals of sufficiently high content to require disposal or reinjection. In addition, before oilfield brine can be used for any beneficial purpose, it must be processed to remover residual petroleum material. The potential for reclaiming water from oil and gas produced waste streams for beneficial use in agriculture and commercial industry prompted research at Texas A&M University.

The Problem

The goal of the project was to develop improved reverse osmosis (RO) membrane filtration technology for treating wastewater produced during oil and gas operations. Objectives included evaluation of a new pretreatment technology using combinations of liquid-liquid centrifuges, organoclay absorbents, and microfiltration and the evaluation and modification of different oil-resistant trans-membrane pressure and recycling ratios to permit optimization of a process design.

The Solution

The research program for this project has been completed. The goals of the project have been met. The technology transfer portion of the project will be satisfied through a commercialization partnership with a new oilfield service company. The desalination technology developed through the project has been licensed to GeoPure Water Technologies, LLC. GeoPure has commissioned a larger-scale mobile unit designed for delivery of 20 gallons per minute (gpm), or 18,800 gallons per day, to be used in field operations.

The Results

The unit has been on site in Johnson County, TX, for the past 2 months and has achieved satisfactory results in desalinating fracturing fluid flow-back brine recovered from Barnett Shale well completions.

The new system is capable of treating wastewater at the rate of 20 gpm and incorporates cartridge filters, microfiltration membranes, a dedicated hydrocarbon removal system, and reverse osmosis membranes. It is now being used to demonstrate the capabilities of the technology by processing sample batches of water for clients at the GeoPure test laboratory and by purifying produced water at clients’ field sites. In conjunction with the construction of a demonstration system, GeoPure also began a marketing program targeted to the Texas oil and gas industry, as well as groundwater users in west Texas. The marketing program includes papers given in industry conferences, such as the International Petroleum Environmental Conference and International Association of Drilling Contractors; a marketing booth; published articles; and company-dedicated marketing presentations.

As a result of this marketing effort, GeoPure is now working with over 30 clients in various stages of feasibility studies. GeoPure has also completed its first commercial oilfield wastewater treatment system in Texas. The system was installed at a location in Benbrook, TX, and is now processing over 200 gpm of feed water, consisting of a combination of fracturing fluid and mud pit slurry. GeoPure designed, constructed, and sold the treatment system to handle feed water where suspended solids have already been removed. The GeoPure system consists of a mechanical filtration step, microfiltration membranes, Mycelex hydrocarbon removal system, and RO membranes. It is equipped with monitoring and automatic shutoff controls for maximum performance and safety. While the 200 gpm system was being constructed, GeoPure deployed its 20 gpm demonstration system to serve as an interim fluid handling solution. A Texas A&M microfiltration system was added to increase the interim treatment capacity. The table below shows analysis of brine water treated in the field with the 20 gpm unit.

Starting in February 2007, GeoPure will begin a series of field tests for clients in Canada, Oregon, Wyoming, and Oklahoma to prove the capability of the treatment technology. The 20 gpm demonstration unit has been mounted in a travel-friendly container that can be shipped to locations without damaging components. The clients range from service companies to oil and gas operators, including a coalbed methane producer.

The Benefits

The benefits of desalination of oilfield brine coming from well completions in the Barnet Shale are significant. Currently the Barnett Shale play is the most active drilling and production area in the Nation. More than 2,000 wells are planned for the 2007 year period, with the majority of the wells being drilled in populated areas. Massive hydraulic fracturing is used to stimulate horizontal wells, where many of the fracs are multi-stage and require as much as 5,000,000 gallons of fresh water. Competition for scarce fresh water has caused conflict among local citizenry, and anger is building toward operators.

Operating companies can utilize the Texas A&M technology offered by GeoPure Water Technologies to re-use frac brines and eliminate many of the environmental objections to drilling in populated areas.