Preparation and evaluation of amine terminated polyether shale inhibitor for water-based drilling fluid

Abstract

Facing the problems of shale hydration, swelling and borehole wall instability in shale gas drilling, a new type of amine terminated polyether (ATPE) shale inhibitor used in water-based drilling fluid is successfully synthesized through the method of leaving group. Using the yield of ATPE as index, orthogonal experiments are designed to determine the optimal reaction conditions. When the mole ratio of polyethylene glycol tosylate (PEG-OTs)/ethylenediamine is 1/3.6, mole ratio of PEG-OTs/triethylamine (acid binding agent) is 1/4, reaction time is 3.5 h and reaction temperature is 60 °C, the yield of ATPE is 91.12%. The structure and molecular weight of polyethylene glycol (PEG-400, a kind of oligomer), PEG-OTs and ATPE are characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy (H 1-NMR) and time of flight mass spectrometer. The characterization results show that the ATPE has a reasonable molecular weight, and the both hydroxyls of PEG-400 have been replaced by ethylenediamine. The inhibition property of ATPE, potassium chloride (KCl), potassium formate (KCOOH), methane-siliconic acid (FMS-1) and polymeric alcohol (JLX-B) are comparatively evaluated through shale rolling dispersion experiment, linear expansion experiment and laser particle size test. The results show that the ATPE has a better shale inhibition property than traditional inhibitors. The drilling fluid system performance evaluation results show that the system has good engineering application value with excellent rheological property, low fluid loss and good shale inhibition property, which guarantee the well-bore stability in shale gas drilling.

Fluorescence Behavior and Mechanisms of Poly(ethylene glycol) and Their Applications in Fe3+ and Cr6+ Detections, Data Encryption, and Cell Imaging

“…The spectra of P8k (Figure 6) showed chemical shift was around 3.7 ppm for the methene (−CH 2 −) protons of PEG chains. 66,67 The resonance peak, centered at 3.705 ppm at 5 mg/mL concentration, shifted gradually with increase in concentration, and appeared at 3.721 ppm at concentration of 200 mg/mL. This remarkable shift toward higher chemical shift constitutes a solid support that the electron density around the ethylene protons was decreasing with increased PEG concentration, owing to likely the electron clouds shifting around C−H bonds toward the ether O atoms (C−O−C), because the increased sharing or through-space conjugation of the electrons, due to the cluster formation.…”

The Structure and Properties of a Novel Hydroxyl‐Terminated Hyperbranched Polymer for Inhibiting Shale Hydration

“…It revealed that β‐CD‐HBP‐OH was not a proper inhibitor for crystalline hydration due to its larger molecular size. Although some inorganic salt inhibitors and linear polymer inhibitors were reported to decrease the interlayer spacing d 001 of wet bentonite for restricting crystalline hydration, it seemed that the molecular weight of hyperbranched polymer dominated the inhibition interaction types. Greater molecular weight meaned larger molecular size with more terminal groups.…”

“…Hence, it is essential to inhibit the hydration and dispersion of shale in the drilling process. In recent decades, literature reports that KCl, CaCl 2 , nanoparticles, ionic liquid, cellulose derivative, polyethyleneimine, polyoxyalkyleneamine, amine‐terminated polymer, polyols and nonionic molecules/polymers have been acted as inhibitors for shale hydration. Among them, amine‐terminated inhibitors are attractive due to their high performance with low dosage.…”

Properties and mechanism of a poly(ionic liquid) inhibitor contained bi‐functional groups for bentonite hydration

“…[48][49][50][51][52][53] Other functional monomers such as N,N-diallylbenzylamine, 47 styrene, 48 and N-vinylpyrrolidone 49 have improved the thermal stability and chemical stability of final copolymers. From another perspective, primary amine, [55][56][57] and quaternary ammonium 44,50,51 have been main inhibitory groups for decades, and it is innovative to develop novel functional groups to inhibit bentonite hydration.…”