Automation of the Drilling Fluid Mixing Process, Field Experiences and Development from North Sea Operations

2011 ◽  
Author(s):  
Ove Kvame ◽  
Bjarne Blom-jensen ◽  
Yngve Bastesen ◽  
Jan-Erik Sandvik
Keyword(s):  
North Sea ◽  
Drilling Fluid ◽  
Field Experiences ◽  
Fluid Mixing ◽  
Mixing Process

Flow Loop Investigation of Lubricant Concentration Effect on Mechanical Friction in Drilling Fluids

2016 ◽  
Author(s):  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Knud Richard Gyland ◽  
Bjørnar Lund ◽  
Sneha Sayindla ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
North Sea ◽  
Test Section ◽  
Drilling Fluid ◽  
Drill String ◽  
Drilling Fluids ◽  
Flow Loop ◽  
Steel Tubing ◽  
Steel Sections ◽  
Concrete Elements

A laboratory scale flow loop for drilling applications has been used for evaluating the effect of lubricants on skin friction during drilling and completion with oil based or low solids oil based fluids. The flow loop included a 10 meter long test section with 2″ OD free whirling rotating drill string inside a 4″ ID wellbore made of concrete elements positioned inside a steel tubing. A transparent part of the housing was located in the middle of the test section, separating two steel sections of equal length. The entire test section was mounted on a steel frame which can be tilted from horizontal to 30° inclination. The drilling fluids and additives in these experiments were similar to those used in specific fields in NCS. Friction coefficient was calculated from the measured torque for different flow velocities and rotational velocities and the force perpendicular to the surface caused by the buoyed weight of the string. The main objective of the article has been to quantify the effect on mechanical friction when applying different concentrations of an oil-based lubricant into an ordinary oil based drilling fluid and a low solids oil based drilling fluid used in a North Sea drilling and completion operation.

Effects of discarded drill muds on microbial populations

1987 ◽  
Vol 316 (1181) ◽  
pp. 567-585 ◽  
Keyword(s):  
North Sea ◽  
Drilling Fluid ◽  
Biological Effects ◽  
Close Correlation ◽  
Diesel Oil ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Seabed Sediment ◽  
Sea Bed ◽  
Low Toxicity

Drilling operations from platforms in the North Sea result in the production of large quantities of drill cuttings. These are a variable mixture of rock chippings, clays and original drilling fluids. Drilling mud is cleaned on the platform to remove rock chips before re-use of the mud. The rejected fraction from the clean-up plant (the cuttings) contains some of the base drilling fluid, and this can lead to an organically rich input to the sea-bed. Cuttings are discarded immediately underneath the platform jacket and thus build-up over the natural seabed sediment. In many cases this cuttings pile may cover considerable areas of seabed, leading to seabed biological effects and potential corrosion problems. Different types of cuttings have different environmental impacts, this being partly dependent upon their hydrocarbon component. Diesel-oil based cuttings contain significant amounts of toxic aromatic hydrocarbons, whereas low-toxicity, kerosenebased cuttings contain less. Both types of cuttings support an active microbiological flora, initiated by hydrocarbon oxidation. This paper presents a study of microbiological degradation of hydrocarbons in cuttings piles around two North Sea platforms. Results indicate that there is a close correlation between microbiological activity and hydrocarbon breakdown in the surface of cuttings piles and that both of these parameters reach their maximum values closer to the platform when low-toxicity muds are in use.

ANIMATION OF CHAOTIC MIXING BY A BACKWARD POINCARE CELL-MAP METHOD

2001 ◽  
Vol 11 (07) ◽  
pp. 1953-1960 ◽  
Author(s):  
LINXIANG WANG ◽  
YURUN FAN ◽  
YING CHEN
Keyword(s):  
Nonlinear Dynamical Systems ◽  
Fluid Mixing ◽  
Chaotic Mixing ◽  
Mixing Process ◽  
Cell Mapping ◽  
Color Code ◽  
Nonlinear Dynamical ◽  
Curved Pipe ◽  
Phase Deformation ◽  
A Cell

A Backward Poincare cell-mapping (BPCM) method has been developed for animating chaotic fluid mixing. The chaotic mixing field considered is induced by periodically rotating the secondary flow of incompressible fluids in a curved pipe. The pipe's cross-section is transformed into a cell space where each cell is initially assigned with a color code and mapped by integrating the velocity field forward in time. The mixing process is thus animated efficiently with each cell being painted with its color on a computer screen. We propose the backward Poincare cell-mapping instead of direct Poincare cell-mapping as a useful tool for probing the chaotic fluid mixing and for animating the phase deformation of nonlinear dynamical systems.

Fluid Mixing Control Inside a Y-Shaped Microchannel by Using Electrokinetic Instability

2007 ◽  
Author(s):  
Zheyan Jin ◽  
Hui Hu
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Fluid Mixing ◽  
Critical Voltage ◽  
Mixing Efficiency ◽  
Mixing Process ◽  
Static Electric Field ◽  
Electrokinetic Instability ◽  
Mixing Control ◽  
Static Electric Fields

An experimental study was conducted to further our understanding about the fundamental physics of electrokinetic instability (EKI) and to explore the effectiveness to enhance fluid mixing inside a Y-shaped microchannel by manipulating convective EKI waves. The dependence of the critical voltage of applied static electric field to trig EKI to generate convective EKI waves on the conductivity ratio of the two adjacent streams was quantified at first. The effect of the strength of the applied static electric field on the evolution of the convective EKI waves and fluid mixing process were assessed in terms of scalar concentration fields, shedding frequency of the convective EKI waves and scalar mixing efficiency. The effectiveness of manipulating the convective EKI waves by introducing alternative electric perturbations to the applied static electric fields was also explored for the further enhancement of the fluid mixing process inside the Y-shaped microchannel.

Field Testing of a Cationic Polymer/Brine Drilling Fluid in the North Sea

1992 ◽  
Author(s):  
T.W. Beihoffer ◽  
F.B. Growcock ◽  
C.K. Deem ◽  
D.S. Dorrough ◽  
R.P. Bray ◽  
...  
Keyword(s):  
North Sea ◽  
Drilling Fluid ◽  
Field Testing ◽  
Cationic Polymer ◽  
The North ◽  
The North Sea

Field Experiences in Application of a Novel Relative Permeability Modifier Gel in North Sea Operations

2005 ◽  
Author(s):  
Jonathan James Wylde ◽  
Graham David Williams ◽  
Christian Alexander Shields
Keyword(s):  
Relative Permeability ◽  
North Sea ◽  
Field Experiences

scholarly journals On the Stability of Oil-Based Drilling Fluid: Effect of Oil-Water Ratio

2020 ◽  
Author(s):  
Titus Ntow Ofei ◽  
Itung Cheng ◽  
Bjørnar Lund ◽  
Arild Saasen ◽  
Sigbjørn Sangesland
Keyword(s):  
North Sea ◽  
Storage Stability ◽  
Drilling Fluid ◽  
Stability Index ◽  
Drilling Fluids ◽  
Flow Transition ◽  
Water Based ◽  
Oil Water ◽  
The Stability ◽  
Transition Index

Abstract Drilling fluids are complex mixtures of natural and synthetic chemical compounds used to cool and lubricate the drill bit, clean the wellbore, carry drilled cuttings to the surface, control formation pressure, and improve the function of the drill string and tools in the hole. The two main types of drilling fluids are water-based and oil-based drilling fluids, where the oil-based also include synthetic-based drilling fluids. Many rheological properties of drilling fluids are key parameters that must be controlled during design and operations. The base fluid properties are constructed by the interaction of the emulsified water droplets in combination with organophilic clay particles. The rheological properties resulted from this combination, along with the particle size distribution of weight materials are vital in controlling the physical stability of the microstructure in the drilling fluid. A weak fluid microstructure induces settling and sagging of weight material particles. The presence of sag has relatively often been the cause for gas kicks and oil-based drilling fluids are known to be more vulnerable for sag than water-based drilling fluids. Hence, the shear-dependent viscosity and elasticity of drilling fluids are central properties for the engineers to control the stability of weight material particles in suspension. In this study, we examined the stability of typical oil-based drilling fluids made for North Sea oilfield drilling application with oil-water-ratios (OWR) of 80/20 and 60/40. The structural character of the fluid samples was analyzed both at rest and dynamic conditions via flow and viscosity curves, amplitude sweep, frequency sweep, and time-dependent oscillatory sweep tests using a rheometer with a measuring system applying a grooved bob at atmospheric conditions. A high precision density meter was used to measure the density of the drilling fluid samples before and after each test. The measurement criteria used to rank the fluids stability include the yield stress as measured from flow curves and oscillatory tests, flow transition index, mechanical storage stability index, and dynamic sag index. We observed that between the two drilling fluids, the sample with OWR = 60/40 showed a stable dispersion with stronger network structure as evidenced by higher yield stress and flow transition index values, while the mechanical storage stability index and dynamic sag index recorded lower values. The results of this study enable drilling fluid engineers to design realistic oil-based drilling fluids with stable microstructure to mitigate settling and sagging of weight material particles for North Sea drilling operation.

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