Grant: CCI Applied Research and Development Grants

Steam assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS) are the two main methods adopted for extraction of bitumen deposits. Once through steam generators (OTSGs) are the main work horses used for production of the large volumes steam required for these processes. OTSGs are well suited for the in-situ resource recovery because of their versatile design to convert poor quality, non-potable water to high-quality steam. Elevated concentrations of organic and inorganic impurities, residual oil and suspended particles present in the boiler feed water (BFW) chemistry lead to precipitation of organic and inorganic scales and increased corrosion/erosion in OTSGs, resulting in frequent system shut down for maintenance, incurring huge maintenance costs. To address this, most companies operate OTSGs at low steam quality (75-80%). Improving OTSG performance for higher steam qualities (up to 90%) is imperative for efficient oil sands extraction and greenhouse gas (GHG) emission reduction. Champion-X, a major supplier of specialty chemicals, is keen to solve OTSG scaling issues; their scientists have designed novel chemical formulations that incorporate chelation, nucleation and crystal growth inhibition, and dispersion mechanisms, key to reducing scaling and fouling. In this project between Southern Alberta Institute of Technology (SAIT) and Champion-X, efficacies of certain novel chemical additives to prevent scaling and fouling will be evaluated using SAIT’s unique Steam Laboratory. Dr. Martez’s NSERC-IRCC Chair “In-situ Steam Generation and Clean Technologies” developed three OTSG pilot test rigs to investigate effects of boiler feed water chemistry scaling and fouling in OTSGs through deposit removal, boiler treatment and control studies. These rigs are 1/1000th the size of industrial OTSG, operating at 11 MPa and 314oC. The potential of the novel chemical formulations developed by Champion-X will be tested in SAIT’s OTSG pilot rigs and in addition the mechanisms of scale formation in the presence and absence of treatment will also be investigated. This research will develop new scientific knowledge on scaling and fouling based on retention of ions, including silica, iron, calcium, magnesium and total organic carbon (TOC), their interaction with specialty chemicals, and scale formation in OTSG tubes with an effective reduction method. This will advance Canadian oil and gas operators’ GHG emission reductions and meet Canada’s environmental target