Laboratory study of fluid properties owing to cutting intrusions during horizontal directional drilling

Abstract

During horizontal directional drilling installations, a primary function of drilling fluids is to yield drill cuttings and lubricate the product pipe. This paper presents the results of a research study of drilling fluid parameters, and the filter cake properties associated with drill cutting intrusions. Different sand meshes and field cutting sizes were added to the drilling fluids. Based on the laboratory experiments of eighteen samples including testing drilling fluid rheology and filter cake properties, the influence of drill cuttings on low solid-phase drilling fluid systems were obtained. The results reveal that drilling fluid plastic viscosity values increase with sand content and particle size. The 100-mesh sand exhibits a larger plastic viscosity compared to the 200-mesh sand. This suggests that the coarser the sand, the greater is the plastic viscosity. By contrast, drilling fluids with 200-mesh sand exhibit greater shear forces than the 100-mesh sand. When the sand content is ≥4%, the shear dilution ability of the drilling fluid begins to weaken. The thinnest filter cake is formed after 6 h with a 100-mesh cutting size and 4% sand content. However, when the cutting size changed to 150-mesh and 2% content, the largest filter cake toughness and strength after rolling for 12 h were obtained. Simultaneously, the combination of 200-mesh and 150-mesh with 2%–4% content rolling for 12–24 h indicate different results. For the filter cake thickness, cutting content is the primary influencing factor followed by particle size and gradation. The factor with the least influence is rolling time. We found that rolling time and gradation were the most significant factors affecting the toughness of the filter cake, followed by cutting content. Conversely, particle size exhibits the least influence on filter cake toughness. These results are important to better understand the solid-phase control of drilling fluids in the field. Keywords: Drilling fluid, Filter cake, Drilling cutting, Solid-phase control, Rheology, Horizontal directional drilling