Formulation of Inhibitive Water Based Mud System with Synthesized Graft Copolymer: A Novel Approach to Mitigate the Wellbore Instability Problems in Shale Formation

Abstract

This research paper discusses about the evaluation of carboxymethyl starch-grafted-polyacrylamidecoplymer as a potential drilling mud additive for the drilling of reactive shale formations. The graft copolymer was synthesized via carboxymethylation and free polymerization technique and it was characterized by FTIR, and SEM. Then, it was processed in the development of the WBDMS. Its effect on the rheological and filtration control properties of the formulated mud system was analyzed thoroughly as per API standard procedures. In addition, the shale inhibition properties were investigated with shale recovery test. Further, Core flow tests were carried out to study the formation damage caused by formulated WBDMS. The obtained results revealed that synthesized graft copolymer had shown superior shale inhibition property. The synthesized CMS-g-PAM along with other additives in the developed system had shown remarkable rheological and filtration characteristics. It also exhibited low formation damage, and high shale recovery than the PHPA polymer in the formulated WBDMS. Hence, this synthesized graft copolymer may be used as a potential mud additive in the formulation ofwater based drilling fluid system for drilling the reactive shale formations.

Enhancing the Performance of HPAM Polymer Flooding Using Nano CuO/Nanoclay Blend

“…The CuO NP content was varied in the nanohybrid systems 1 to 5 from 0.1-0.5 g at a constant content of nanoclay of 0.5 g, while the nanoclay content was varied in the nanohybrid systems 6 to 8 from 0.3-0.6 g at a constant CuO NPs of 0.2 g. Figure 4 shows that increasing the content of CuO NPs and the nanoclay increased the viscosity of the HPAM solution significantly. This increase in viscosity is attributed to the effective dispersion of the nanoclay in the HPAM polymer matrix owing to hydrogen bonding between HPAM and the nanoclay [28,36,37], the network structure of the nanohybrid [3], and the adsorption of CuO NPs onto the HPAM (and vice versa) [21], as evident from Figure 2d. Gou et al [28] reported that hydrogen bonds are established between charged oxygen and hydroxyl groups of the nanoclay with the carbonyl group of HPAM.…”

Experimental Research of Shale Pellet Swelling in Nano-Based Drilling Muds

“…Over the past decade, new materials have been developed and studied for usage as additives in drilling mud, like carboxymethyl starch-grafted-polyacrylamide copolymer [21], poly(styreneblock-acrylamide)/organic montmorillonite nanocomposites, nanocomposite bentonite [22] and Tween 80 (T80)/ZnO nanoparticles as nontoxic additives used in drilling fluid [23]. Despite the large quantity of data available through the different laboratory studies and published papers, wellbore instability problems still exist, and further research work is needed to overcome the wellbore instability problem in the future.…”