Field Trials of Reservoir Nanoparticles Reveal Stability, High Rates of Recovery

This article, written by Editorial Manager Adam Wilson, contains highlights of paper SPE 142592, ’Industry First Field Trial of Reservoir Nanoagents,’ by Mazen Y. Kanj, SPE, Saudi Aramco, and M. Harunar Rashid and Emmanuel P. Giannelis, Cornell University, prepared for the 2011 SPE Middle East Oil and Gas Show and Conference, Manama, Bahrain, 25-28 September. The paper has not been peer reviewed. The promise of nanotechnology becomes limitless with the possibility of having functionalized molecular agents to illuminate the reservoir and intervene to alter adverse oil recovery conditions. The future reality of the reservoir nanoagents concept was laboratory and field demonstrated with the industry’s first building block nanoagents’ template. The industry’s first proven reservoir nanoagent template is introduced and demonstrated by means of a push/pull field trial in an observation well. Introduction A milestone achievement on the road to having in-situ reservoir nanoagents features an industry-first building block template named Arab-D Dots (A-Dots). The synthesis is proved to be very amenable for scaling up in support of a field operation. Reservoir Rocks The Jurassic Arab-D is the most prolific oil-bearing formation of the Ghawar field in Saudi Arabia. Ghawar (Fig. 1) is the largest discovered oil field in the world today. From its northern extremity, the field extends southward some 150 miles as essentially one long continuous anticline, approximately 25 miles across at its widest point. The Arab-D formation constitutes one of the main reservoirs of Saudi Arabia and is composed of reservoir-quality limestone and dolomite. The Arab-D reservoir has an average thickness of more than 200 ft. On the finer scale, it can be further subdivided into four major shoaling-upward carbonate cycles (Fig. 1). The A-Dot Particles A-Dots are carbon-based fluorescent nanoparticles. Carbon nanoparticles represent a unique class of nanomaterials that are generally synthesized through a hydrothermal treatment process. Analogous to their well-known cousins, fullerenes and carbon nanotubes, carbon nanoparticles exhibit interesting optical (and electrical) properties that may be exploited in oil and gas applications. A-Dots are developed with a functional stability to survive a lengthy transit in a harsh environment in an oil reservoir, which can be read and interrogated reliably when the nanoparticles are recovered. This translates into required stability at temperatures exceeding 100°C and salinities exceeding 120,000 ppm in total dis-solved solids in the presence of divalent (as well as monovalent) ions such as Ca++, Mg++, and SO4−−.