A Review of Downhole Separation Technology

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractIn recent years, a technique of separating water downhole to reduce the volume of produced water and decrease the chance of surface pollution has been developed. It is called downhole oil-water separation (DOWS) technology. This technique allows water to be separated in the wellbore and injected into a suitable injection zone downhole while oil with traces of water is produced to the surface.Subsequent to the introduction of the DOWS technology to the oil industry in the 1990's, several trial applications have been undertaken to test the technology. These trials allowed significant information to be collected on the feasibility of the DOWS technology. Through the joint efforts of Argonne National Laboratory, CH2M-Hill, and the Nebraska Oil and Gas Conservation Commission, a comprehensive technical report was issued in January 1999 discussing this technology. Additional reports on trial applications and feasibility studies have been presented by various study groups.This paper reviews the status of and issues surrounding the application of downhole separation technology. This review summarizes the various papers and reports dealing with DOWS technology and its application in the oil and gas industry. This technology has the potential to provide significant reductions in produced water as the technology is adopted by the industry. It can also reduce produced water handling costs and increase oil and gas production in the right application. The wide-spread adoption of DOWS technology is dependent on improving the understanding of the process and its applications throughout the oil and gas industry.

Flow structures and their impact on single and dual inlets hydrocyclone performance for oil–water separation

“…2. Since the parts of the cyclone separator do not move during operation, separation is brought about by the development of high centrifugal forces by the help of its geometric design (Ogunsina and Wiggins 2005).…”

“…However, the separation purity can be enhanced by connecting several hydrocyclones in series. Several hydrocyclone separators can also be connected in parallel to handle large volumes of feed (Ogunsina and Wiggins 2005). The division between upward flow carrying the lighter fraction (oil) and downward flow carrying the heavier fraction (water) determines the midsection when a classification (separation) curve is made.…”

Membrane-based downhole oil–water separation (DOWS) technology: an alternative to hydrocyclone-based DOWS

“…Fernández et al (2001) and Tweheyo et al (2003) have worked in the direction of membrane separation technology, and from study it can be judged that through the development in membrane science the membrane-based DOWS could be introduced to the petroleum industry. Based on reservoir characterization and simulation model analysis for future trend analysis specific time, depth and length for deployment of the membrane inside the tubing can be determined (Ogunsina and Wiggins 2005). The proposed mechanism will consist of a thin and porous hydrophobic and oleophilic membrane made from polytetrafluoroethylene (PTFE) (Qing et al 2017), for separation of the inflow and two outflow ports in ultrafiltration modules.…”

“…This will lead to loss in injectivity. As complex and delicate hydrocyclone-based DOWS equipment will be fitted in very small cross-sectional area and as they are exposed to very high flow rate, risk of corrosion/erosion increases (Ogunsina and Wiggins 2005;Gao et al 2007). PTFE can be manufactured using electrospinning and sintering from the colloidal nanoparticle of PTFE-PVA emulsion via nucleation and growth of thin fibrous membrane (Mozaffari et al 2017(Mozaffari et al , 2018Li et al 2018).…”

Experimental study of a vane-type pipe separator for oil–water separation

“…The mentioned process is attractive but needs further investigation about the structure optimization of separator for the limited space in the well-bore. Traditional downhole separator is hydrocyclone which is a kind of tangential inlet structure combining with a long small cone tail and an upflow tube (Ogunsina and Wiggins, 2005). According to the number of tangential inlets, traditional hydrocyclone could be classified into two types: "multi-inlet" (Jiang et al, 2002) and "single-entry".…”