Hydrophobic‐associated polymer‐based laponite nanolayered silicate composite as filtrate reducer for water‐based drilling fluid at high temperature

Laponite®-From Dispersion to Gel-Structure, Properties, and Applications

Laponite® (LAP) is an intensively studied synthetic clay due to the versatility given by its layered structure, which makes it usable in various applications. This review describes the multifaceted properties and applications of LAP in aqueous dispersions and gel systems. The first sections of the review discuss the LAP structure and the interactions between clay discs in an aqueous medium under different conditions (such as ionic strength, pH, temperature, and the addition of polymers) in order to understand the function of clay in tailoring the properties of the designed material. Additionally, the review explores the aging phenomenon characteristic of LAP aqueous dispersions as well as the development of shake-gels by incorporating LAP. The second part shows the most recent studies on materials containing LAP with possible applicability in the drilling industry, cosmetics or care products industry, and biomedical fields. By elucidating the remarkable versatility and ease of integration of LAP into various matrices, this review underscores its significance as a key ingredient for the creation of next-generation materials with tailored functionalities.

Functional Gels and Chemicals Used in Oil and Gas Drilling Engineering: A Status and Prospective

Research into functional gels and chemicals and their applications represents a cutting-edge international field of study. For example, investigating how they can be applied in oil and gas drilling (and extraction engineering) and developing novel functional chemical materials for the oil field could provide innovative solutions and technological methods for oil and gas drilling and extraction operations. Through a literature analysis, this paper presents a review of the current research status and application scenarios of different types of functional gels and chemicals, both domestically and internationally. The classification and preparation principles of various functional materials are systematically outlined and the current applications of functional gels and chemicals in oil and gas drilling and extraction engineering are introduced. These applications include drilling and plugging, enhanced oil recovery, water plugging, and profile control. The formation mechanisms and application scenarios of different types of gels and chemicals are also analyzed and summarized, with a discussion of their prospects in oil and gas drilling and extraction engineering. We broaden the scope of functional gels and chemicals by exploring new application fields and promoting the development of different types of gels and chemicals in a more intelligent direction.

A Thermal-Responsive Zwitterionic Polymer Gel as a Filtrate Reducer for Water-Based Drilling Fluids

It is crucial to address the performance deterioration of water-based drilling fluids (WDFs) in situations of excessive salinity and high temperature while extracting deep oil and gas deposits. The focus of research in the area of drilling fluid has always been on filter reducers that are temperature and salt resistant. In this study, a copolymer gel (PAND) was synthesized using acrylamide, N-isopropyl acrylamide, and 3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate through free-radical polymerization. The copolymer gel was then studied using FTIR, NMR, TGA, and element analysis. The PAND solution demonstrated temperature and salt stimulus response characteristics on rheology because of the hydrophobic association effect of temperature-sensitive monomers and the anti-polyelectrolyte action of zwitterionic monomers. Even in conditions with high temperatures (180 °C) and high salinities (30 wt% NaCl solution), the water-based drilling fluid with 1 wt% PAND displayed exceptional rheological and filtration properties. Zeta potential and scanning electron microscopy (SEM) were used to investigate the mechanism of filtration reduction. The results indicated that PAND could enhance bentonite particle colloidal stability, prevent bentonite particle aggregation, and form a compact mud cake, all of which are crucial for reducing the filtration volume of water-based drilling fluid. The PAND exhibit excellent potential for application in deep and ultra-deep drilling engineering, and this research may offer new thoughts on the use of zwitterionic polymer gel in the development of smart water-based drilling fluid.

Nano-laponite/polymer composite as filtration reducer on water-based drilling fluid and mechanism study

In drilling deep complex formations, most drilling fluid additives have insufficient temperature and salt tolerance, resulting in the decline of drilling fluid performance. This study used 2-acrylamide-2-methylpropane sulfonic acid, acrylamide, dimethyl diallyl ammonium chloride and modified nano-laponite to synthesize a nanocomposite filtrate reducer (ANDP) with excellent temperature and salt resistance, which can maintain the performance of drilling fluid. The structure of ANDP was analysed by a transmission electron microscope and an infrared spectrometer. The thermal stability of ANDP was studied by thermogravimetric analysis. The performance of ANDP was evaluated in a water-based drilling fluid. The mechanism was analysed per clay particle size distribution, Zeta potential, filter cake permeability and scanning electron microscopy imaging. The results show that ANDP has good thermal stability and the expected molecular structure. The filtration of freshwater drilling fluid after ageing at 200°C is 10.4 ml and that of saturated brine drilling fluid is 6.4 ml after ageing at 150°C. Mechanism analysis suggests that the ANDP increases the thickness of clay particle hydration layer and maintains the colloidal stability of the drilling fluid. ANDP inhibits the agglomeration of clay particles and significantly reduces the filtration by forming dense mud cake.

Synthesis of a Low-Molecular-Weight Filtrate Reducer and Its Mechanism for Improving High Temperature Resistance of Water-Based Drilling Fluid Gel System

During the exploitation of deep and ultradeep oil and gas resources, the high-temperature problem of deep reservoirs has become a major challenge for water-based drilling fluids. In this study, a novel high-temperature-resistant filtrate reducer (LDMS) with low molecular weight was synthesized using N, N-dimethylacrylamide; sodium p-styrene sulfonate; and maleic anhydride, which can maintain the performance of a drilling fluid gel system under high temperature. Unlike the conventional high-temperature-resistant polymer filtrate reducer, LDMS does not significantly increase the viscosity and yield point of the drilling fluid gel systems. After aging at 210 °C, the filtrate volume of a drilling fluid with 2 wt% LDMS was only 8.0 mL. The mechanism of LDMS was studied by particle size distribution of a drilling fluid gel system, Zeta potential change, adsorption experiment, change of bentonite interlayer spacing, filter cake scanning electron microscope, and related theoretical analysis. The mechanism study revealed that LDMS could be adsorbed on the surface of bentonite particles in large quantities and intercalated into the interlayer of bentonite. Thus, it can improve the hydration degree of bentonite particles and the colloidal stability of the drilling fluid gel system, maintain the content of fine particles in the drilling fluid gel system, form a compact mud cake, and significantly reduce the filtrate volume of the drilling fluid gel system. Therefore, this work will promote the application of a low-molecular-weight polymer filtrate reducer in high-temperature-resistant water-based drilling fluid gel systems.