Effect of Buoyancy and Inertia on Viscoplastic Fluid: Fluid Displacement in an Inclined Eccentric Annulus With an Irregular Section

2018 ◽  
Author(s):  
Steinar Kragset ◽  
Hans Joakim Skadsem
Keyword(s):  
Drilling Fluid ◽  
Mass Density ◽  
Density Difference ◽  
Regular Part ◽  
Viscoplastic Fluid ◽  
Drilling Fluids ◽  
Displacement Efficiency ◽  
Cement Slurry ◽  
Horizontal Section ◽  
Primary Cementing

Primary cementing is an important well construction process that should establish well control barriers and zonal isolation. Critical for primary cementing is the successful displacement of drilling fluid from the annulus between casing and formation by a sequence of spacer fluids and cement slurry. Failure to displace the drilling fluid may compromise the annular cement integrity and result in contaminated cement with degraded mechanical properties. Issues such as eccentricity, washouts and other geometric irregularities in the wellbore can complicate the displacement processes, and their effect on the quality of the cementing job and the final result is linked to uncertainty. We present numerical simulations of the displacement process between two viscoplastic fluids in the vicinity of a symmetric local hole enlargement. The study is limited to laminar flow regimes in the regular part of the annulus, and we focus on a near-horizontal section with significant eccentricity and small annular clearance. We vary the volumetric flow rate and the mass density difference between the fluids, and study how the irregularity affects the displacement efficiency and the presence of residual fluid in and after the irregularity. In the regular part of the geometry, eccentricity favors flow in the wider, upper part of the annulus, while density difference leads to azimuthal flow from the top to the low side of the annulus. The results support the assumption that increasing the mass density difference improves the displacement efficiency. In the laminar regime, lower flow rates can be favorable over higher ones in terms of efficiency measured as a function of volume that is pumped into the enlarged section. Displacement of drilling fluids for primary cementing is a rich flow problem involving different non-Newtonian fluids and possibly irregular geometry. Simulations of the displacement process can aid in optimizing fluid properties and injection rates for primary cementing operations, and assist cement log interpretation after the operation.

Effect of Buoyancy and Inertia on Viscoplastic Fluid-Fluid Displacement in an Eccentric Annulus With an Irregular Section: Part 2 — Displacements in Vertical Annulus

2019 ◽  
Author(s):  
Hans Joakim Skadsem ◽  
Steinar Kragset
Keyword(s):  
Drilling Fluid ◽  
Mass Density ◽  
Volumetric Flow Rate ◽  
Density Difference ◽  
Viscoplastic Fluid ◽  
Positive Density ◽  
Displacement Efficiency ◽  
Cement Slurry ◽  
Narrow Side ◽  
Vertical Annulus

Abstract Casing strings and liners are important subsurface structural components in petroleum and in geothermal wells. After the casing string has been run in hole, it is cemented to the formation by pumping a sequence of spacer fluids and cement slurry into the annulus outside the string. Spacer fluids are usually pumped ahead of the cement slurry in order to displace the drilling fluid from the annulus that is to be cemented, and thereby avoid contamination of the cement slurry. Fluid displacements are governed by inertia, buoyancy and viscosity effects, in addition to being strongly influenced by the annular geometry. Poor centralization of the casing or irregularities such as washouts can influence the displacement flows both locally and over long axial distances. We present three dimensional numerical simulations of the displacement flow involving two viscoplastic fluids in the vicinity of a symmetric local hole enlargement. We focus on laminar flow regimes in the regular part of the annulus and investigate how the volumetric flow rate and the mass density difference between the fluids affect the displacement efficiency in the regular and the irregular parts of the annulus. This study considers viscoplastic displacement flows in a near-vertical, irregular annulus and is an extension of a previous publication that focused on a near-horizontal annulus. We contextualize our simulations by comparison to industry guidelines for effective and steady laminar displacements in the regular, near-vertical annulus. Here, eccentricity favors flow in the wider sector of the annulus while a positive density difference between the fluids generates secondary, azimuthal flow toward the narrow side of the annulus. In the enlarged and irregular section, both the axial bulk velocity and casing eccentricity decrease sharply and buoyancy becomes more pronounced compared to in the regular annulus. We quantify and discuss the effects of local hole enlargements on displacement efficiencies. Simulations of cementing flows can aid in optimizing fluid properties and pump rates, including when the wellbore has suspected or confirmed zones of irregular geometries.

scholarly journals Effect of Buoyancy and Inertia on Viscoplastic Fluid–Fluid Displacements in a Regular and an Irregular Eccentric Annulus

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Hans Joakim Skadsem ◽  
Steinar Kragset
Keyword(s):  
Drilling Fluid ◽  
Mass Density ◽  
Three Dimensional ◽  
Density Difference ◽  
Viscoplastic Fluid ◽  
Positive Density ◽  
Displacement Efficiency ◽  
Cement Slurry ◽  
Eccentric Annulus ◽  
Narrow Side

Abstract Casing strings and liners are important subsurface structural components in petroleum and in geothermal wells. After the casing string has been run in hole, it is cemented to the formation by pumping a sequence of spacer fluids and cement slurry into the annulus outside the string. Spacer fluids are usually pumped ahead of the cement slurry to displace the drilling fluid from the annulus that is to be cemented and thereby avoid contamination of the cement slurry. Fluid displacements are governed by inertia, buoyancy, and viscosity effects, in addition to being strongly influenced by the annular geometry. Poor centralization of the casing or irregularities such as washouts can influence the displacement flows both locally and over long axial distances. We present three-dimensional numerical simulations of the displacement flow involving two viscoplastic fluids in the vicinity of a symmetric local hole enlargement. We focus on laminar flow regimes in the regular part of the annulus and investigate how the volumetric flowrate and the mass density difference between the fluids affect the displacement efficiency in the regular and the irregular parts of the annulus. This study considers viscoplastic displacement flows in a near-vertical, irregular annulus and is an extension of a previous publication that focused on a near-horizontal annulus. We contextualize our simulations by comparison to industry guidelines for effective and steady laminar displacements in the regular, near-vertical annulus. Here, eccentricity favors flow in the wider sector of the annulus, while a positive density difference between the fluids generates secondary, azimuthal flow toward the narrow side of the annulus. In the enlarged and irregular section, both the axial bulk velocity and casing eccentricity decrease sharply and buoyancy becomes more pronounced compared to in the regular annulus. We quantify and discuss the effects of local hole enlargements on displacement efficiencies. Simulations of cementing flows can aid in optimizing fluid properties and pump rates, including when the wellbore has suspected or confirmed zones of irregular geometries.

scholarly journals Application of Microemulsion Systems in the Formulation of Biodegradable Pre-Flush Fluid for Primary Cementing

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4683
Author(s):  
Elayne A. Araújo ◽  
Thaine T. Caminha ◽  
Evanice M. Paiva ◽  
Raphael R. Silva ◽  
Júlio Cézar O. Freitas ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Xrd Analysis ◽  
Oil Well ◽  
Cement Slurry ◽  
Removal Time ◽  
Primary Cementing ◽  
Flush Fluid ◽  
Cake Removal

Oil well cleanup fluids (pre-flushes) are intermediate fluids pumped ahead of the cement slurry; they are able to clean the well walls by removing the filter cake formed by the drilling fluid, and leave the surface water-wet. This work’s main objective was to use biodegradable microemulsion systems as cleanup fluids in order to reduce the environmental impact. Three microemulsion systems were formulated, each composed of an oil phase, a surfactant and three different aqueous phases: glycerol, glycerol:water (mass ratio 1:1), and fresh water. The results show that all microemulsion systems were effective with 100% filter cake removal, with a removal time of less than 60 s. The wettability test and fluid compatibility analyses exhibited advantageous performances, without phase separation, variations in viscosity, gelation, or flocculation. The compressive strength and X-ray diffractometry (XRD) analysis showed the influence of the glycerol on the cement slurry properties, with the compressive strength resistance ranging from 8.0 to 10.7 MPa, and resulted in the formation of portlandite.

Impact of Physical and Chemical Mud Contamination on Cement-Formation Shear Bond Strength

2014 ◽  
Author(s):  
Arome Oyibo ◽  
Mileva Radonjic
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Chemical Contamination ◽  
Cement Slurry ◽  
Liquid Form ◽  
Sustained Casing Pressure ◽  
Physical And Chemical ◽  
The Impact

The purpose of this experimental study is to investigate the impact of physical and chemical mud contaminations on cement-formation bond strength for different types of formations. Physical contamination occurs when drilling fluids (mud) dries on the surface of the formation forming a mud cake while chemical contamination on the other hand occurs when drilling fluids which is still in the liquid form interacts chemically with the cement during a cementing job. Wellbore cement has been used to provide well integrity through zonal isolation in oil & gas wells and geothermal wells. It has also used to provide mechanical support for the casing and protect the casing from corrosive fluids. Failure of cement could be caused by several factors ranging from poor cementing, failure to completely displace the drilling fluids to failure due to casing. A failed cement job could result in creation of cracks/micro annulus through which formation fluids could migrate to the surface which could lead to sustained casing pressure, contamination of fresh water aquifer and blow out in some cases. To achieve proper cementing, the drilling fluid should be completely displaced by the cement slurry. However, this is hard to achieve in practice, some mud is usually left on the wellbore which ends up contaminating the cement. This study focuses on the impact of contamination on the shear bond strength and the changes in the mineralogy of the cement at the cement-formation interface.

scholarly journals Automated Characterization of Non-Newtonian Fluids Using Laboratory Setup

2020 ◽  
Vol 30 (1) ◽  
pp. 39-53
Author(s):  
Dan Sui ◽  
Juan Carlos Martinez Vidaur
Keyword(s):  
Vertical Section ◽  
Drilling Fluid ◽  
Experimental Tests ◽  
Drilling Fluids ◽  
Horizontal Section ◽  
Good Opportunity ◽  
Laboratory Setup ◽  
Fluid Properties ◽  
Mathematical Algorithms ◽  
Basic Objective

AbstractThe automation towards drilling fluid properties’ measurement has been pursued in the recent years in order to increase drilling efficiency with less human intervention. Adequately monitoring and adjusting density and rheology of drilling fluids are fundamental responsibilities of mud engineers. In this study, experimental tests that automatically characterize fluids were conducted. The basic objective is to measure the differential pressures along two sections of the pipes: one horizontal section and one vertical section. Using such measuring data, mathematical algorithms are then proposed to estimate fluids’ density and subsequently viscosity with respect to flow regimes, laminar and turbulence. The results were compared and validated with the values measured on rotational rheometers. With the help of models and numerical schemes, the work presented in the paper reveals a good opportunity to improve the accuracy and precision of continuous-measuring and monitoring fluids’ properties.

The "U-Type" Wells History of Fuzzy Ball Drilling Fluids for CBM Drilling in China

2013 ◽  
Vol 748 ◽  
pp. 1273-1276 ◽  
Author(s):  
Ben Guang Guo ◽  
Li Hui Zheng ◽  
Shang Zhi Meng ◽  
Zhi Heng Zhang
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Ordos Basin ◽  
Coal Bed ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Horizontal Section ◽  
Lost Circulation ◽  
Well Bore Stability ◽  
Formation Damage Control

The fuzzy ball drilling fluids have been developed on the basis of the circulation foam and Aphron to control lost circulation effectively. There are some difficulties in drilling U-type well, such as well-bore stability, cutting carrying problem, large torque and friction at the horizontal section, and formation damage to coal-bed. The objective of this paper was to show some applications of fuzzy ball drilling fluids on U-type wells of the Ordos Basin and prove the superiority of fuzzy ball drilling fluid in CBM drilling. To the three mentioned cases, the density of fuzzy ball drilling fluid was 0.90~1.18g/cm3, the funnel viscosity was 45~72s, the dynamic shear force was 12~19 Pa, the PV was 13~19mPa·s and the pH was ranged from 7 to 9. To use the fuzzy ball drilling fluids, the average ROP increased above 10% with no borehole complexity, such as stuck pipe, hole enlargement causing poor cleaning and etc. These cases reflected excellent properties of the fuzzy ball drilling fluids including effectively sealing, good carrying and suspension ability, formation damage control and compatible weighted by inert materials. Furthermore, the fuzzy ball drilling fluids will not affect BHA tools like motors and MWD in CBM drilling.

Inline Setup Provides Automatic Measurement of PVT Behavior of Drilling Fluids

2021 ◽  
Vol 73 (11) ◽  
pp. 55-56
Author(s):  
Chris Carpenter
Keyword(s):  
Temperature Dependence ◽  
Drilling Fluid ◽  
Mass Density ◽  
Automatic Measurement ◽  
Heating Element ◽  
Drilling Fluids ◽  
Systematic Bias ◽  
Temperature Conditions ◽  
True Value ◽  
Pvt Behavior

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 204084, “Automatic Measurement of the Dependence on Pressure and Temperature of the Mass Density of Drilling Fluids,” by Eric Cayeux, SPE, NORCE, prepared for the 2021 SPE/IADC International Drilling Conference and Exhibition, originally scheduled to be held in Stavanger, 9–11 March. The paper has not been peer reviewed. The mass density of drilling fluids usually is measured manually with a mud balance. The pressure and temperature dependence of the mass density of the fluid [i.e. its pressure/volume/temperature (PVT) behavior] then is estimated. Variations in the composition of the fluid mix and uncertainties regarding the PVT behavior of each component, however, may lead to inaccuracies. An apparatus that measures the PVT behavior of the drilling fluid contained in a pit directly and automatically has been designed. Inline PVT Measurement The pressure and temperature dependence of drilling fluids can be described by a biquadratic function. However, API Recommended Practice 13D recommends using a linear function of temperature combined with a quadratic form of pressure. Because this process involves six parameters, at least six measurements must be made under different conditions of pressure and temperature. A starting point is to measure the mass density of the fluid under six different pairs of pressures and temperatures. To keep the design of the apparatus as simple as possible, it ideally would not operate under high-pressure and -temperature conditions. Therefore, knowing the range of pressures and temperatures sufficient for taking sample measurements is useful in order to be able to extrapolate the model at higher pressure and temperature conditions with acceptable accuracy. The densitometer’s measurement precision of 0.05 kg/m3 and repeatability of 0.01 kg/m3 is known, so stochastic simulations of the possible measurement error for various spans of investigated pressures and temperatures can be performed. In this study, the authors con-sider that the calibrated PVT model shall be used for a range of pressure of 1000 bar and a range of temperature of 200°C. It is possible to calculate the root mean square of the proportion error between the predicted density value and the “true” value when varying stochastically the systematic bias on the density measurement when the calibration samples are spanning small ranges of pressure and temperature. A possible design for an inline apparatus could be to pump the drilling fluid past a controllable heating element and having a controllable choke downstream of the densitometer apply a pressure while measuring the mass density. The setpoints for the heating element and the choke would be changed six times in order to collect the necessary mass densities to calibrate the PVT model. Changing the temperature of the heating element, however, can require several minutes, and gathering a complete set of calibration measurements may easily take 15 to 30 minutes. An alternative could be to perform six measurements simultaneously. The densitometers can be mounted in series. The configuration could be with six parallel branches or any combinations between series and parallel branches. With two parallel branches, in one branch the temperature of the fluid is not modified, while it is modified in the second branch. For each of the two branches, back pressure is applied at two intermediate positions. This configuration has the advantage of using fewer chokes and pressure sensors (four instead of five).

scholarly journals A Review of Recent Research on Contamination of Oil Well Cement with Oil-based Drilling Fluid and the Need of New and Accurate Correlations

2020 ◽  
Vol 4 (2) ◽  
pp. 28
Author(s):  
Nachiket Arbad ◽  
Catalin Teodoriu
Keyword(s):  
Drilling Fluid ◽  
Initial Study ◽  
Diesel Oil ◽  
Drilling Fluids ◽  
Oil Well ◽  
Cement Slurry ◽  
Oil Well Cement ◽  
Well Cement ◽  
Research Studies

Drilling fluids and oil well cement are important well barriers. Their compatibility affects the long-term integrity of the well. The mixing of drilling fluid with the oil well cement causes contamination of oil well cement. If the contamination is due to diesel/oil-based drilling fluid (OBF) it adversely affects the rheological and mechanical properties of oil well cement—in other words, the long-term integrity of the well. An initial study on OBF contamination of oil well cement was carried out two decades ago. In recent years, several research projects were carried out on the same topic to understand the reason for changes in the properties of oil well cement with OBF contamination. This literature review shows that using OBF eliminates several drilling problems, as the long-term integrity of the well depends on the amount of OBF contamination in the cement slurry. This paper compares the experiments performed, results and conclusions drawn from selected research studies on OBF contamination of oil well cement. Their shortcomings and a way forward are discussed in detail. A critical review of these research studies highlights the need for new and accurate correlations for OBF-contaminated oil well cement to predict the long-term integrity of wells.

Impact of Conventional Practices on Economic Efficiency as Illustrated by the Construction of Horizontal Sections of Multilateral ERD Wells and Fishbone Wells in Western Siberia

2021 ◽  
Author(s):  
Maxim Pavlovich Frolov ◽  
Dmitry Nikolaevich Voitenko ◽  
Alexander Olegovich Proshin ◽  
Anastasiya Andreevna Ivanova ◽  
Vitaly Igorevich Shepelev ◽  
...  
Keyword(s):  
Western Siberia ◽  
Drilling Fluid ◽  
Collaborative Work ◽  
Integrated Approach ◽  
Drilling Fluids ◽  
Fluid Composition ◽  
Technological Parameters ◽  
Horizontal Section ◽  
Low Viscosity ◽  
Drilling Conditions

Abstract This paper is a detailed description of the first experience of an ERD wells horizontal section using ultra-low-viscosity drilling fluid as a drilling fluid implemented in the Russia land. This work has great value as an experience that allows to reevaluate the traditional views on the sole influence of drilling fluid parameters on the process of drilling wells. The thesis considers the key aspects and practices of improving the technical and economy values of drilling the multilateral ERD wells and FishBone wells in Western Siberia by applying an integrated approach based on three key factors: understanding the features of the rheology of drilling fluids; thorough analysis of the results of modeling wellbore washing and cleaning and comparing the calculated values with the actual values of the determined technological parameters in order to predict and control ECD; the collaborative work of the customer and the contractor, so-called "active supervising" methodology, aimed on making timely decisions for adjusting of the target requirements during the wells construction, "in situ" method, in order to achieve the made goals. The main conclusions have been made during the work: Effective and sufficient cleaning of annular space can be achieved with minimum values of drilling fluid rheology characteristics. Cuttings and marble bridging agent participate in the filter cake creation. The absence of marble bridging agent particles in the mud composition cannot be a reason of complications (absorption, sticking) when drilling low-permeability reservoirs. The concentration of the marble bridging agent should be determined, taking into account several factors: solids control equipment efficiency, formation permeability, density and drilling fluid composition. the recommended values for the parameters such as lubricant concentration and MBT, must be selected, firstly, based on comprehensive understanding of the idea of each parameter, and secondly, adequately assessing their significance under specific drilling conditions. Competent active supervising of drilling fluid has huge impact on the economy efficiency of well construction, whereas this approach can be beneficial for both the customer and the drilling fluid contractor. The implemented on the project approach allowed to save up to 60% for the cost of 1m3 of drilling fluid for horizontal section, as well as to reduce the time spent on the wells construction. The main result of the work: two multilateral wells were successfully drilled with the DDI of 7.2 and 6.55 and high risks of lost circulation. Wells construction was completed by running the liner to the target bottom without any signs of landings. However, the most important achievement is the emerging prospect of replicating the proposed approach to drilling ERD wells for deeper deposits development, that allows us to expect comparable technical and economy effects considering drilling conditions.

Automatic Measurement of the Dependence on Pressure and Temperature of the Mass Density of Drilling Fluids

2021 ◽  
Author(s):  
Eric Cayeux
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Speed Of Sound ◽  
Drilling Fluid ◽  
Mass Density ◽  
Adiabatic Compressibility ◽  
Drilling Fluids ◽  
Pvt Behavior

Abstract Drilling fluids are subjected to large variations of pressure and temperature while they are circulated in a well. This span of pressures and temperatures is so large that the mass density of the drilling mud differs from one depth to another. For a precise estimation of the hydrostatic and hydrodynamic pressures, it is therefore important to have a good estimation of the pressure and temperature dependence of the mass density of drilling fluids. Usually, the mass density of drilling fluids is manually measured with a mud balance. The pressure and temperature dependence of the mass density of the fluid, i.e. its PVT behavior, is then estimated based on the PVT behavior of its components and their relative proportions. However, variations in the composition of the fluid mix and uncertainties on the PVT behavior of each components, may lead to inaccuracies. To circumvent these limitations, an apparatus that measures directly and automatically the PVT behavior of the drilling fluid contained in a pit has been designed. The setup measures both the mass density and the speed of sound in the fluid at specific conditions of pressure and temperature. From the speed of sound in the liquid mix, it is possible to estimate the adiabatic compressibility. The device also utilizes a heat exchanger from which the thermal conductivity and specific heat capacity of the drilling fluid can be estimated. Combining the specific heat capacity, thermal conductivity and the adiabatic compressibility, the isothermal compressibility can be calculated. By combining measurements made at different conditions of pressure and temperature, a PVT model of the drilling fluid is estimated. By providing automatically, and on a continuous basis, the actual PVT behavior of drilling fluids, drilling automation systems can gain in precision and at the same time, their configuration can be simplified, therefore making them more accessible to any drilling operation.

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