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Use of Environment-Friendly Additives for Improving the Properties of Water-Based Mud for Drilling Reactive Formations
Published in Subrata Borgohain Gogoi, Advances in Petroleum Technology, 2020
Bichakshan Borah, Borkha Mech Das
Funnel viscosity or Marsh funnel viscosity is used to determine the viscosity of mud instantly in the field. It consists of a cone-shaped mud having a mesh at the top to remove any solid particles entering the funnel or mug and a cup. We poured 950 ml of drilling mud through the mesh in the funnel, and the time required to complete discharge the mud was measured by a stopwatch. In this process, by considering the density and the time, three types, that is, effective viscosity as in Eq. 13.1, apparent viscosity (considering time) and apparent viscosity (considering both time and viscosity), can be calculated using Eqs. 13.2–13.3, respectively, as follows: effectiveviscosity=ρ(t−25)cpApparentviscosity=−0.0118t2+1.6175t−32.168Apparentviscosity=ρ(t−28)cp,
Horizontal directional drilling: lessons learned in conduit installations
Published in Mark Knight, Neil Thomson, Underground Infrastructure Research, 2020
On a series of HDD bores along an industrial street, contractors had been experiencing difficulty generating returns and were consequently having difficulty pulling back anything but short lengths of pipe. Once on-site, it was determined that the contractor was using a drilling fluid composed of liquid polymers in water, with marsh funnel viscosities in the neighborhood of 30 to 35 seconds per quart (1 quart = 0.95 L). As was briefly discussed in section 3.7 above, polymer-based drilling fluids are best suited to predominantly clayey conditions. When asked about his choice of fluids, the contractor’s response was that while digging the entry and exit pits for the bores, he had encountered only stiff clays, and assumed that they would be the dominant subsurface unit. Had the contractor consulted the geotechnical summaries attached to the plans, he would have discovered that this clay layer only extended to a depth of approximately 1.5 m, and was underlain by predominantly sandy soils. Bentonite-based drilling fluids are better suited to predominantly sandy conditions, owing to their superior gel strengths which allow them to suspend and transport coarse-grained materials. A more viscous (45 to 50 seconds per quart), bentonite-based drilling fluid was recommended, with the result that consistent returns were obtained and the contractor was able to complete longer bores.
Optimization of cuttings slurry system for re-injection of oil-based drilling cuttings
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Sun Mengying, Deng Jingen, Ma Chengyun, Feng Yongcun, Li Bin, Geng Tie
The re-injection fluid system contains two major types of substances, one is the oil-based mud to be treated, and the other is the additive. The main components of oil-based mud are oil-based drilling fluid and cuttings produced during drilling. There are two types of additives: main agent and auxiliary agent. The main agent is a thickener, and the auxiliaries are fluid loss agent and defoamer. According to the requirements of oilfield re-injection, the particle size of the solid phase should be less than 300 microns, the density should be between 1.0 and 1.2 g/cm3, the viscosity of the Marsh funnel should be 90–120 s, no solid sedimentation should occur within 24 h. The marsh funnel viscosimeter is a device used to measure drilling fluid viscosity in accordance with API standards. The measurement principle is to calculate the time it takes for 946 ml of fluid to flow freely out of a fixed-type funnel when gravity is at action. Second (s) is the unit here. The viscosity range is 50–100 mPa·s, and the slurry filtration is within 10 ml (Huang et al. 2018; Zhang 2018). The detailed additive types and performance indicators of the re-injection slurry are shown in Figure 2.
Development of a nano-based drilling fluid using copper nanoparticles for Upper Assam formations: rheological interpretation
Published in Petroleum Science and Technology, 2022
Debashree Dutta, Shailaj Bharadwaj, Dhiraj Kumar, Borkha Mech Das
WDF was prepared by using bentonite clay where its concentration was varied from 1% to 4% by mass. A mud mixture was used for the purpose where mixing was done for 10 min. Rheological analysis was conducted initially for the base mud and the results have been tabulated as shown in Table 1. Synthesized CNPs of various concentrations were added to the selected optimum WDF, thereby resulting in the formulation of different CNDFs. Viscometer was used for the rheological analyses of CNDFs. It is a multiple speed viscometer from where plastic viscosity (PV), YP, and GS can be measured. Marsh funnel viscosity (MFV) was measured using a marsh funnel. Funnel viscosity is the time (in s) required for one quart of mud to flow out of a Marsh funnel. It is reported in seconds. PV, YP, and apparent viscosity (AV) were evaluated using the following formulae: