Effect of Asphaltene Aggregation on Rheological Properties of Diluted Athabasca Bitumen

Since almost all drilling problems directly or indirectly relate to drilling fluid, improvement in drilling fluid significantly enhances drilling operations. Drilling fluid contains base fluid, suspended solid particles and chemicals. Recently, nanoparticles have been widely recommended for improvement in drilling fluid properties. The main purpose of this study was to improve the rheological and filtration properties of water-based drilling fluid through adding new additive carboxyl methyl cellulose (CMC)/polystyrene core-shell nanocomposite. It compares filtration and rheological behavior of CMC, nanoCMC and core-shell nanocomposite. The core-shell nanocomposite was synthesized by miniemulsion polymerization method, and nanoCMC and core-shell nanocomposite were characterized by scanning electron microscope, transmission electron microscopy, particle size analyzer and thermogravimetric analysis. Fluid loss, mud cake thickness, viscosity, weight and pH of drilling fluid with core-shell nanocomposite additive were compared with conventional CMC (bulk CMC) and nanoCMC particles. Results showed a significant decrease in mud cake thickness and fluid loss when the core-shell nanocomposite was used, as compared with conventional CMC and nanoCMC. Viscosity of three additives has same trend with insignificant change while less yield point is obtained for drilling fluid containing core-shell nanocomposites. Mud weight and pH were almost the same for all three additives. Thus, the core-shell nanocomposite can be an alternative additive to control mud cake thickness and fluid loss while maintaining other main properties in an acceptable range.

Section: Mud Weight and Phmentioning

confidence: 99%

Improvement in filtration properties of water-based drilling fluid by nanocarboxymethyl cellulose/polystyrene core–shell nanocomposite

Saboori

Sabbaghi

Kalantariasl

et al. 2018

“…6), the foams behavior in porous media resulted in rheological properties that are different to these observed in bulk. As suggested and demonstrated by Mozaffari et al (2015 and, the use of micro-and nano-fluidic devices offer opportunities to bridge such gap in rheological studies. Nonetheless, with oil (1) MRF = ΔP foam ΔP 2-phase Fig.…”

Section: Mobility Reductionmentioning

confidence: 99%

Development and evaluation of foam-based conformance control for a high-salinity and high-temperature carbonate

Fuseni

AlSofi

Al-Julaih

et al. 2018

The extreme heterogeneity of carbonate reservoirs in the form of fracture corridors and super-permeability thief zones present challenges to the efficient sweep of oil in both secondary and tertiary recovery operations. In such reservoirs, conformance control is crucial to ensure injected water and any EOR chemicals optimally contact the remaining oil with minimal throughput. Foam-based conformance control is a relatively new technology especially its use for deep diversion in high-salinity and high-temperature conditions. In this work, a laboratory study was conducted to develop and evaluate a foam-based conformance control technology for application in a high-salinity and high-temperature carbonate. Foaming agents (surfactants) were first screened for their suitability with regard to reservoir temperature and salinity where properties such as foamability and foam stability were measured. The best performing surfactants were then used to study the foam-induced mobility reduction across a core composite. The experiments were conducted at reservoir conditions. Foam stability and decay were also investigated in those permeability reduction experiments. Brine and crude oil were injected after foam formation where observed pressure drops allowed quantification of foam stability and decay; hence, the sustainability of mobility reduction. Finally, the potential improvement in reservoir contact and hence oil recovery were examined by oil displacement experiments conducted in specially prepared heterogeneous composites. For the studied conditions of high salinity and high temperature, foaming agents of the amphoteric family as well as one manufacturer proprietary surfactants blend were found suitable in terms of salt tolerance and foam stability. Using the proprietary blend and without oil in core, the generated foam reduced fluids mobility by a factor of 12. The attained mobility reduction was lower in presence of oil but was still acceptable for flow diversion purposes. Using the proprietary blend and with oil in core, the generated foam reduced fluids mobility by a factor of 6 (compared to 12 without oil in core). Oil recovery improvement with foam placement was also found to be significant. These results demonstrate the potential of foams for carbonates with harsh salinity and temperature conditions.

“…(Chengshou et al 2010;Fufeng et al 2008;Li et al 2015). Mozaffari et al (2015) proposed that other factors which significantly affect the production rate in fractured carbonated reservoirs are the capillary force of liquid in microand nano-sized channels which might be blocked by the asphaltene. Due to their results, bitumen solution was used to lessen the amount of asphaltene viscosity and in some occasions leads to the elimination the asphaltene precipitation from the small pores of bulk volume (Lesueur 2009;Mozaffari et al 2015).…”

Section: Introductionmentioning

confidence: 99%

“…Mozaffari et al (2015) proposed that other factors which significantly affect the production rate in fractured carbonated reservoirs are the capillary force of liquid in microand nano-sized channels which might be blocked by the asphaltene. Due to their results, bitumen solution was used to lessen the amount of asphaltene viscosity and in some occasions leads to the elimination the asphaltene precipitation from the small pores of bulk volume (Lesueur 2009;Mozaffari et al 2015). They go on arguing that bitumen is directly affected the contact angle and the smallest amount of yield stress is a negative key parameter in distinguishing between Newtonian and non-Newtonian Bingham plastic behavior (Han et al 2006;Saeed Mozaffari et al 2017;Yang et al 2016).…”

Section: Introductionmentioning

confidence: 99%

An experimental study of acidizing operation performances on the wellbore productivity index enhancement

Rabbani

Davarpanah

Memariani

2018

The hydrocarbon fossil fuels are considered as the preferable fuels to provide sufficient energies for industrial purposes. Also, extracting oil from the exploration wells might be a concerning issue in the coming decades, and petroleum engineers push themselves into limits ind novel solutions to enhance the oil recovery factor. Wellbore stimulation procedures exert a profound impact on the current production rate enhancement; respect of the way, reservoir productivity index witnesses a steep rise during the production operation and subsequently would virtually eliminate unnecessary expenditures of other methodologies. Appropriate investigation of acidizing procedures and its significant role in the wellbore production enhancement are utterly dependent on the quality and types of additives, types of acid, acidizing operation and types of formation. The objective of this study is to investigate the effect of injected acid in the carbonated reservoir and subsequently its comparison with the acidizing operations model. Therefore, available well-testing experiments are administered to determine the critical reservoir parameters such as skin factor, reservoir pressure, and permeability. Since then by modeling the wellbore condition in the acidizing operation simulator software, the impact of acidizing on the reservoir is simulated. Consequently, the provided information from software is compared with the real data from well-testing operations. As a result, productivity index is increased dramatically owing to successful acidizing procedures.