Properties of Bentonite Slurry Drilling Fluid in Shallow Formations of Deepwater Wells and the Optimization of Its Wellbore Strengthening Ability While Drilling

Abstract

Offshore oil- and gas-field development is shifting from shallow water to deepwater on a large scale. Deepwater shallow bentonite slurry drilling fluid has a single composition and a simple structure. Therefore, the bentonite slurry drilling fluid has been neglected for the shallow wellbore strengthening ability. Based on the shallow geological characteristics and bentonite hydration mechanism, considering the economy and application effect, the optimization of bentonite slurry drilling fluid from four aspects of viscosity enhancement, adsorption, trapping, and physical plugging to carry out deepwater shallow wellbore strengthening research has been undertaken. For an indoor simulation of bentonite slurry and its drilling slurry-making process using a 2–10% mass concentration of bentonite slurry drilling fluid, laser particle size analysis found an interesting phenomenon different from the traditional understanding: for every 5% increase in particle size accumulation in the range of 0.1–100 μm, the bentonite slurry particle size increases linearly. Based on this interesting phenomenon, the basic performance of drilling fluids with different concentrations of bentonite slurry was evaluated. Experiments were conducted to introduce cationic emulsified asphalt as a deformation filler and to explore a new inexpensive drilling and wellbore strengthening material, AEH-P. The effectiveness of deepwater shallow strengthening was evaluated for AEH-P and cationic emulsified asphalt from both mechanistic and experimental aspects. It is obvious that the wellbore strengthening effect is the result of both particle settling and particle size matching. By exploring the relationship among bentonite slurry hydration dispersion, the charged nature, particle concentration, and the wellbore strengthening effect, a set of low-cost deepwater shallow bentonite slurry drilling fluids with a good wellbore strengthening effect are constructed. The research results provide a method to strengthen the wellbore for the subsequent fast and efficient drilling of deepwater shallow wells, further improving the drilling efficiency.

Reviewing the advancements in offshore drilling technologies in the USA and their global impact

“…This includes the use of advanced technologies for detecting offshore drilling rigs and extracting information from satellite imagery to monitor offshore platforms and ensure environmental safety (Zhu et al, 2021;Wang et al, 2019). Furthermore, the optimization of drilling fluid properties, such as bentonite slurry, is being studied to improve wellbore strengthening ability during drilling operations in deepwater wells (Xu et al, 2022). Additionally, the structural optimization design of modular double drill pipes is being explored to enhance drilling operations (Wang & Guo, 2022).…”

Preparation and Application of New Polyhydroxy Ammonium Shale Hydration Inhibitor

“…Montmorillonite contains a lot of water. With an increase in temperature, the adsorbed water, interlayer water and hydroxyl water in montmorillonite are removed in turn [35,36]. Therefore, TGA can be used to determine the weight loss rate of montmorillonite treated with different inhibitors, so as to evaluate the effect of inhibitors on the water absorption, hydration swelling and dispersion of montmorillonite.…”

Mud Cake Improver Mul-GX with Lubrication and Interface Enhancement Effect and Its Action Mechanism

“…In order to solve the problem of the poor quality of mud cake leading to weak cementing interface, mud cake removal method and mud cake modification method are mainly developed . At present, technologies such as MTC, , MTA, and MCS have been developed to improve cementing quality based on the mud cake modification method, the essence of which is to add improvers to the drilling fluid to improve the quality of mud cake, thus improving the cementing strength of the second interface of cementing. , However, there have been no reports on improving the lubrication of wellbore mud cakes. In summary, the existing technology of adding liquid lubricants to improve wellbore lubrication is only considered from the perspective of reducing wellbore friction, ignoring the problem that the lubricant deteriorates the quality of the shaft lining mud cake.…”