Synthesis of a Dendrimer as Rheological Modifier for Deep-Water Drilling Fluids and Study of its Interaction with Organo-Clay at Different Temperatures

Abstract

As the influence of large temperature range during deep-water drilling on rheological properties of water-in-oil emulsified drilling fluids, a dendrimer synthesized from a dodecyl dibasic acid and triethylenetetramine was introduced as a rheological modifier to get a flat-rheology. The product was characterized by infrared spectroscopy and its interaction with organo-clay was studied with sedimentation experiment, optical microscope, X-ray diffraction (XRD), Transmission electron microscopy (TEM), and rheological test. The results showed that the dendrimer can improve the dispersion of organo-clay in oil and increase the distance between layers. What’s more, the addition of dendrimer can balance the yield point of base slurry (consisted of mineral oil, aqueous solution of 30wt% CaCl2, mixed emulsifier, and organo-clay) at 4 ° C and 65 ° C.

An Amphiphilic Multiblock Polymer as a High-Temperature Gelling Agent for Oil-Based Drilling Fluids and Its Mechanism of Action

“…Oil-based drilling fluids, typified by a brine dispersal phase and a continuous phase of base oils such as mineral, diesel, or synthetic oils-amalgamated with apt emulsifiers, wetting agents, gelling agents, and density enhancers-constitute a robust oil-in-water emulsifying system [5][6][7][8][9]. Despite their less prevalent utilization compared to Gels 2023, 9, 966 2 of 19 water-based variants, oil-based drilling fluids are distinguished by their enhanced wellbore stability, inhibition efficacy, lubricative properties, and thermal fortitude, rendering them the preferred option for drilling in unconventional reservoirs, intricate geological structures, and extreme temperature and pressure conditions [10][11][12].…”

Improving the Weak Gel Structure of an Oil-Based Drilling Fluid by Using a Polyamide Wax

“…Drilling fluids are expected to have a weak gel structure [ 7 , 8 , 9 , 10 ]. At a low shear rate, the viscosity is high, which is beneficial to suspend drill cuttings; at a high shear rate, the viscosity is low, which is conducive to fast drilling.…”

“…Ma et al [ 16 ] synthesized a new oil-soluble polymer by suspension polymerization using methyl styrene, methyl methacrylate, stearyl acrylate, and dimethyl 2,2 azobis isobutyrate as raw materials, which effectively improved the yield point of OBDFs under 180 °C conditions. Shi et al [ 7 ] synthesized a dendritic polymer with dodecyl dibasic acid and trientine as the raw materials, which effectively improved the rheology of the OBDFs and the dispersion of organoclay in the oil. However, polymer-based rheology modifiers have a significant influence on the viscosity of drilling fluids, and this situation is not conducive to the regulation of rheology under high-density conditions.…”