The objective of this study is to experimentally explore activated carbon as an enabler for microwave applications in the oilfield industry. Although using microwave overcomes major challenges associated with other widely applied techniques to produce heavy oil reservoirs, it has its own limitations. Activated carbon can be used as a microwave enabler to improve heat penetration depth of this microwave-assisted thermal EOR method. This paper presents an experimental investigation of activated carbon thermal-electromagnetic characteristics and proposes two heating mechanisms to improve its performance. In addition, heating synthetic rocks with and without activated carbon is investigated.

In this work, activated carbon samples in granular form are heated using a conventional 2.45-GHz microwave oven with a maximum power level of 1,200 watts. The temperature of heated activated carbon is monitored and compared to heating other naturally existing materials in oil reservoirs (oil, water, rock). Experimental results shows that oil and rock are almost transparent to microwave, and activated carbon heats up to very high temperatures in a very short period of time. A 20-ml sample of activated carbon heats up from 70°F to 800°F in 40 seconds which is much higher than water (~185°F) and oil (~90°F). Experimental results also show that heating activated carbon with two proposed mechanisms would decrease the required time to reach a specific temperature by up to 50%. Namely they are pre-heating and pre-mixing it with water. Both techniques and potential causes of the observed improvement are presented and investigated.

Further experimental investigation in this study involves making synthetic rocks filled with activated carbon in different ways. It is applied either in proppants form to fill an induced fracture or is injected into the rock sample in the form of nanoparticles. Temperature monitoring for both cases shows that using activated carbon would improve the generated heat and penetration depth.

Combining activated carbon and microwave resolves major challenges associated with other thermal EOR techniques. This work provides us with a better understanding of an important component of this microwave-assisted method. This will result in developing better programs for future laboratory investigations and field deployments of this technique.

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