Innovative Use of Kaolinite in Downhole Scale Management: Squeeze Life Enhancement and Water Shutoff

Abstract

Applied research has been undertaken to examine the potential of kaolinite combined with a kaolinite fixation agent to;Increase squeeze lifetime through alteration of near wellbore surface characteristics and mineralogy and,Provide water shut off control. With respect to enhancing squeeze lifetime, it is documented that kaolinite increases the quantity of inhibitor adsorbed. Conversely, clean sandstone with low clay content commonly provides a poor substrate for adsorption. Furthermore, in reservoirs that experience near wellbore formation damage due to kaolinite mobilisation, it has been shown that use of a fixation agent as part of a squeeze treatment can increase squeeze lifetime. Using these facts, research has assessed the feasibility of injecting microcrystalline kaolinite (average particle size 2 µm) combined with the fixation agent and scale inhibitor as a means of mechanically altering near wellbore mineralogy and surface property characteristics within clean, high permeability sandstones. The testing has been designed to mimic the squeeze procedure used in the field for performing such a job and involves no additional steps to that used in a normal squeeze, i.e. Pre-Flush ? Main Treatment ? Over-Flush. The paper presents the results of coreflood experiments that have been undertaken to demonstrate "proof of concept" for the above along with examples of potential field applications. A further concept, born from the initial idea, was the use of kaolinite and fixation agent for efficient, low cost, environmentally friendly water shutoff. There are several available products for water shutoff but the disadvantage of these is that they are not acceptable for use in Norway due to poor environmental characteristics. Hence, there was a need to fill this gap by developing water shutoff technology to meet country specific environmental legislation. The paper provides details of coreflood testing, where an excess of kaolinite has been used to form an internal and external filter cake that is attached to the wellbore face and within the near wellbore using the fixation agent. The paper draws on data from StatoilHydro operated fields in order to highlight the potential of this innovative approach to downhole scale management and water control.

Carbon Nanotubes: A New Methodology for Enhanced Squeeze Lifetime CNTs

“…However, effects of ethanol, DMF and DCC can be easily neglected due to washing process at different stages in the NAST coreflood experiments. The only remaining chemical that could affect the results was aminosilane of which the influence was previously studied [10,11].However these studies cannot be compared due to different experimental conditions. This is the subject of future work to investigate the effect on aminosilane on NAST coreflood results.…”

“…One organosilane was utilised in the oil field in order to increase the adsorption of SI as a fixing agent [10,11]. In this work the key point is to pre-treat the rock surface to have a covalent bond with CNTs.…”

“…3-aminopropyltriethoxysilane is one of the common silanes that has the potential to be used in NAST. Also, 3-aminopropyltriethoxysilane has been used to bond to kaolinite and to increase adsorption of SI [10,11].…”

“…Recently, attempts to improve squeeze treatments and increase squeeze lifetime have been made by a number of means including using crosslinking the inhibitors [2], increasing the pH of the aqueous solution by adding additives [3,4], employing inhibitor particles [5], boosting precipitation and adsorption by additives [6,7], using calcium in precipitation squeeze treatment [8,9] and more recent new ideas such as using fixing agents [10], altering the rock mineralogy [11] and employing nano-particles for further displacement [1].…”

Advances of Nanotechnologies in Oil and Gas Industries

“…Squeeze lifetimes, and extension of such, are important for improving scale management. There are some researches trying to prolong the lifetime of a squeeze treatment by cross-linking inhibitors (Bache and Nilsson, 2000), enhancing additive's precipitation and adsorption (Rabaioli and Lockhart, 1996) or applying kaolinite to modify near wellbore surface properties (Fleming et al, 2009).…”