Preparation of a supramolecular sand-inhibiting and water-control agent and study of its applicability to oil reservoirs

To solve the problem whereby an oil reservoir with applicable boundaries of the current sand-inhibiting and water-control agent is unclear, a supramolecular sand-inhibiting and water-control agent PDKM was prepared using acrylamide (AM), methacryloxyethyltrimethyl ammonium chloride (DMC), styrene (SM), and γ-methacryloyloxypropyltrimethoxysilane (KH570) as comonomers. The molecular structure of PDKM was verified by 1H-NMR and FT-IR. On the basis of establishing an evaluation method that can screen the performance of sand-inhibiting agent at a flow rate of 100 mL/min, the oil reservoir applicable boundaries of PDKM were obtained through the evaluation of sand-inhibiting and water-control performance. The experimental results show that when the concentration of PDKM is 5000 mg/L, the oil reservoir conditions are temperature ≤90 °C, formation water salinity ≤21,249 mg/L, the degree of sand production corresponding to slight sand production and particle migration, crude oil viscosity ≤50 mPa·s, primary water flooding water cut ≥75%, and formation permeability contrast ≤2. The performance with respect to sand inhibiting and water control can all reach an excellent level. Therefore, the PDKM solves the problem whereby the applicability of the current sand-inhibiting and water-control agent is unclear, and provides direction for the selection of suitable products in the oilfield production site.