Estimation of Undisturbed Geothermal Gradient in Wells From Measured Drilling Data: A Numerical Approach

2017 ◽  
Author(s):  
Lucas Cantinelli Sevillano ◽  
Jesus De Andrade ◽  
Sigbjørn Sangesland
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Geothermal Gradient ◽  
Computer Code ◽  
Numerical Approach ◽  
Rock Properties ◽  
Drilling Fluids

The undisturbed geothermal gradient is a key thermal boundary that drives heat transfer processes occurring in oil and gas wells throughout their lifetime. However, the temperature distribution with depth is somewhat uncertain, and this is often assumed to be a linear approximation from the mudline to the bottom of the well. During drilling, the circulating temperature may significantly affect the rheology of the drilling fluids and the cement setting processes. Therefore, erroneous estimates of the wellbore temperature may affect the overall performance of the drilling phase and subsequent well operations. Further, it is important to know the accurate temperature distribution within the formation for assessment of the petroleum prospectivity through source rock maturation and reservoir quality. This paper presents a numerical methodology to estimate the undisturbed geothermal gradient while drilling in offshore wells. This methodology may also be applied to onshore wells by simplification. The new approach is based on an in-house axisymmetric wellbore transient thermal model, in which the equations are solved using the finite difference method. The model computes the heat transfer between the well and riser system with the surroundings. However, other computational codes may also be used following the framework presented in this study. The computer code should provide a detailed representation of the geometry of the wellbore, the physical properties of the drilling fluid and formation, the suitable thermal boundary conditions and temporal discretization. The temperatures of the fluid at the inlet of the drillstring and at the bottom hole assembly (BHA), in the annulus A, are used as input to the numerical model that iteratively adjusts the undisturbed geothermal gradient, which generated the temperature recordings while drilling. The paper comprises cases studies of hypothetical wells drilled in relevant offshore areas in the world, each with their distinctive and variable geothermal gradient, defined by the different rock formations encountered. Uncertainties regarding the thermal properties of the rock were also considered to ascertain the robustness of the code. The water depth of the drilling site was also observed to impact the convergence of the algorithm. The results obtained by the numerical approach are in good agreement with the expected values of the undisturbed formation temperatures. The novelty of the numerical framework is the ability to provide reliable and satisfactory estimates of the undisturbed geothermal gradient for wellbores with any configuration, lithology and rock properties. These estimates are based on temperature measurements of the circulating drilling fluid at the BHA and account for uncertainty in rock thermal properties; in reasonable time using standard engineering computers.

ENVIRONMENTAL DRILLING SOLUTIONS ON THE POLYMERIC BASIS

2020 ◽  
Author(s):  
E.A. Flik ◽  
◽  
Y.E. Kolodyazhnaya
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Oil And Gas Industry ◽  
Environmental Safety ◽  
Drilling Fluids ◽  
Gas Industry ◽  
Fluid Systems ◽  
Water Based

The article assesses the environmental safety of drilling fluids that are currently widely used in the oil and gas industry. It shows active development of water-based drilling fluid systems using xanthan biopolymer.

Heat Moisture Modified Rice Flours as Additive in Drilling Fluids

2021 ◽  
Vol 80 (1) ◽  
pp. 62-72
Author(s):  
Bunyami Shafie ◽  
Lee Huei Hong ◽  
Phene Neoh Pei Nee ◽  
Fatin Hana Naning ◽  
Tze Jin Wong ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Low Cost ◽  
Health Concern ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Fluid Mixture ◽  
Gas Drilling ◽  
Water Based ◽  
Rice Flours

Drilling mud is a dense, viscous fluid mixture used in oil and gas drilling operations to bring rock cuttings to the earth's surface from the boreholes as well as to lubricate and cool the drill bit. Water-based mud is commonly used due to its relatively inexpensive and easy to dispose of. However, several components and additives in the muds become increasingly cautious and restricted. Starch was introduced as a safe and biodegradable additive into the water-based drilling fluid, in line with an environmental health concern. In this study, the suitability of four local rice flours and their heat moistures derivatives to be incorporated in the formulation of water-based drilling fluid was investigated. They were selected due to their natural amylose contents (waxy, low, intermediate, and high). They were also heat moisture treated to increase their amylose contents. Results showed that the addition of the rice flours into water-based mud significantly reduced the density, viscosity, and filtrate volume. However, the gel strength of the mud was increased. The rice flours, either native or heat moisture treated, could serve as additives to provide a variety of low cost and environmentally friendly drilling fluids to be incorporated and fitted into different drilling activity.

Numerical Simulation Model of Electrothermal De-Icing Process on Composite Substrate

2020 ◽  
Author(s):  
Xiaofeng Guo ◽  
Zhiqiang Guo ◽  
Qian Yang ◽  
Wei Dong
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Thermal Properties ◽  
Temperature Distribution ◽  
Simulation Model ◽  
Melting Process ◽  
Ice Melting ◽  
Melted Zone ◽  
Composite Substrate ◽  
Cfrp Composite

Abstract A numerical simulation model of electrothermal de-icing process on carbon fiber reinforced polymer (CFRP) composite is conducted to study the effect of thermal properties of the substrate on the ice melting process. A novel melting model which is based on the enthalpy-porosity method is applied to study the transient ice melting process and heat transfer of the de-icing sys-tem. Multi-layered electrothermal de-icing systems including composites with different fiber orientation are used to analyze the effects of orthotropic heat conductivity of the CFRP composite on the ice melting process and heat transfer. Movement of the ice-water interface, the melted zone thickness and the melted zone area on CFRP composite are investigated on the three-dimensional electrothermal de-icing unit. The effects of thermal properties of substrate on the temperature distribution of the ice-airfoil interface are analyzed. The computational results show that the thermal properties of substrates affect the temperature on the ice-airfoil interface, the temperature distribution in the substrate, ice melting area, ice melting rate and ice melting volume significantly. The time that ice starts to melt on the CFRP composite substrate is earlier than that on the metal substrate. However, it takes more time for the ice to melt completely on the ice-CFRP interface than that on the ice-metal inter-face. The orthotropic heat conductivity of CFRP composite results in strong directivity of the melting area on the ice-CFRP in-terface. A ratio parameter is defined to represent the matching degree of substrate materials and geometry model of de-icing system. The simulation model can be applied to study electrothermal de-icing system of nacelle inlet and airfoil made of composite. The results in present work is also helpful to predict the change of temperature during de-icing process and provide guidelines for the optimizing the electrothermal de-icing system to reduce power consumption according to the fiber structure of composite.

Well Clean-Up Using a Combined Thermochemical/Chelating Agent Fluids

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Mohamed Mahmoud
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Chelating Agent ◽  
Drilling Fluids ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Different Types ◽  
Cake Removal

The well clean-up process involves the removal of impermeable filter cake from the formation face. This process is essential to allow the formation fluids to flow from the reservoir to the wellbore. Different types of drilling fluids such as oil- and water-based drilling fluids are used to drill oil and gas wells. These drilling fluids are weighted with different weighting materials such as bentonite, calcium carbonate, and barite. The filter cake that forms on the formation face consists mainly of the drilling fluid weighting materials (around 90%), and the rest is other additives such as polymers or oil in the case of oil-base drilling fluids. The process of filter cake removal is very complicated because it involves more than one stage due to the compatibility issues of the fluids used to remove the filter cake. Different formulations were used to remove different types of filter cake, but the problem with these methods is the removal efficiency or the compatibility. In this paper, a new method was developed to remove different types of filter cakes and to clean-up oil and gas wells after drilling operations. Thermochemical fluids that consist of two inert salts when mixed together will generate very high pressure and high temperature in addition to hot water and hot nitrogen. These fluids are sodium nitrate and ammonium chloride. The filter cake was formed using barite and calcite water- and oil-based drilling fluids at high pressure and high temperature. The removal process started by injecting 500 ml of the two salts and left for different time periods from 6 to 24 h. The results of this study showed that the newly developed method of thermochemical removed the filter cake after 6 h with a removal efficiency of 89 wt% for the barite filter cake in the water-based drilling fluid. The mechanisms of removal using the combined solution of thermochemical fluid and ethylenediamine tetra-acetic acid (EDTA) chelating agent were explained by the generation of a strong pressure pulse that disturbed the filter cake and the generation of the high temperature that enhanced the barite dissolution and polymer degradation. This solution for filter cake removal works for reservoir temperatures greater than 100 °C.

Flow Pattern and Heat Transfer in a Closed Rotating Annulus

1994 ◽  
Vol 116 (3) ◽  
pp. 542-547 ◽  
Author(s):  
D. Bohn ◽  
G. H. Dibelius ◽  
E. Deuker ◽  
R. Emunds
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Side Wall ◽  
Computer Code ◽  
Turbine Rotor ◽  
Base Case ◽  
Convection Flow ◽  
Coriolis Forces ◽  
R Ratio ◽  
Temperature Levels

The prediction of the temperature distribution in a gas turbine rotor containing gasfilled closed cavities, for example between two disks, has to account for the heat transfer conditions encountered inside these cavities. In an entirely closed annulus no forced convection is present, but a strong natural convection flow occurs induced by a nonuniform density distribution in the centrifugal force field. A computer code has been developed and applied to a rotating annulus with square cross section as a base case. The co-axial heat flux from one side wall to the other was modeled assuming constant temperature distribution at each wall but at different temperature levels. Additionally the inner and outer walls were assumed to be adiabatic. The code was first verified for the annulus approaching the plane square cavity in the gravitational field, i.e., the ratio of the radius r over the distance h between outer and inner cylindrical wall was set very large. The results obtained agree with De Vahl Davis’ benchmark solution. By reducing the inner radius to zero, the results could be compared with Chew’s computation of a closed rotating cylinder, and again good agreement was found. Parametric studies were carried out varying the Grashof number Gr, the rotational Reynolds number Re, and the r/h ratio, i.e., the curvature of the annulus. A decrease of this ratio at constant Gr and Re number results in a decrease of heat transfer due to the Coriolis forces attenuating the relative gas velocity. The same effect can be obtained by increasing the Re number with the h/r ratio and the Gr number being constant. By inserting radial walls into the cavity the influence of the Coriolis forces is reduced, resulting in an increase of heat transfer.

scholarly journals Utilization of metakaolin-based geopolymer as a mud-cake solidification agent to enhance the bonding strength of oil well cement–formation interface

2020 ◽  
Vol 7 (2) ◽  
pp. 191230
Author(s):  
Yuhuan Bu ◽  
Rui Ma ◽  
Jiapei Du ◽  
Shenglai Guo ◽  
Huajie Liu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Bonding Strength ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Research Work ◽  
Drilling Fluids ◽  
Oil Well ◽  
Mud Cake ◽  
Calculation Methodology ◽  
Zonal Isolation

This research work designed a novel mud-cake solidification method to improve the zonal isolation of oil and gas wells. The calculation methodology of mud-cake compressive strength was proposed. The optimal formula of activator and solid precursors, the proper activating time and the best activator concentration were determined by the compressive strength test. The effects of solid precursors on the properties of drilling fluid were evaluated. Test results show that the respective percentage of bentonite, metakaolin, slag and activator is 1 : 1 : 0.3 : 0.8, as well as the optimum ratio of Na 2 SiO 3 /NaOH is 40 : 1. The optimum concentration of activator is 0.21 and the activating time should be more than 10 min. The solid precursors did not show any bad influence on the rheological property of drilling fluids. Even though the compressive strength decreased when the solid precursors blended with barite, the strength values can still achieve 8 MPa. The reaction of metakaolin and activator formed cross-link structure in the mud-cake matrix, which enhanced the connection of the loose bentonite particles, lead to the significant enhancement of shear bonding strength and hydraulic bonding strength. This mud-cake solidification method provides a new approach to improve the quality of zonal isolation.

Nano-Enhanced Drilling Fluids: Pioneering Approach to Overcome Uncompromising Drilling Problems

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
J. Abdo ◽  
M. Danish Haneef
Keyword(s):  
Rheological Properties ◽  
Size Distribution ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Lost Circulation ◽  
Drilling Operations ◽  
Cost Efficient ◽  
A Chain ◽  
Size Distribution Of Particles

The idea of pushing the limits of drilling oil and gas wells by improving drilling fluids for undemanding and cost efficient drilling operations by extracting advantage from the wonders of nanotechnology forms the basis of the work presented here. Foremost, in order to highlight the significance of reducing the size distribution of particles, new clay ATR which has a chain like structure and offers enormous surface area and increased reactivity was tested in different sizes that were chemically and mechanically milled. Bentonite which is a commonly used drilling fluid additive was also tested in different particle size distribution (PSD) and rheological properties were tested. Significant reduction in viscosity with small sized particles was recorded. The tested material called ATR throughout this paper is shown to offer better functionality than bentonite without the requirement of other expensive additives. Experiments were performed with different size distributions and compositions and drastic changes in rheological properties are observed. A detailed investigation of the shear thinning behavior was also carried out with ATR samples in order to confirm its functionality for eliminating the problem of mechanical and differential pipe sticking, while retaining suitable viscosity and density for avoidance of problems like lost circulation, poor hole cleaning and inappropriate operating hydrostatic pressures.

Influence of Rock Chemical Composition in Microwave Heating and Decontamination of Drill Cuttings

2017 ◽  
Vol 899 ◽  
pp. 469-473 ◽  
Author(s):  
Irineu Petri Jr. ◽  
Jéssika Marina dos Santos ◽  
Arley Silva Rossi ◽  
Marina Seixas Pereira ◽  
Claudio Roberto Duarte ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Electromagnetic Waves ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Microwave Drying ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Heating Unit ◽  
Drill Cuttings ◽  
Gas Drilling

Drill cuttings generated by oil and gas drilling process are incorporated into the drilling fluid to ensure an efficient drilling and solids removal. The drilling rigs have a separation system accountable for separating drill cuttings and drilling fluids. Microwave drying is a new technology of separation that has been studied as an alternative to the currently drill cuttings dryer used. The results obtained in preliminary studies showed that this microwave drying is sensitive to different oxides presents into the rock. Thus, this study aimed to describe the microwave heating kinetics of some rocks in order to verify the interaction of oxides with electromagnetic waves. For this, the oxide contents of the rocks were determined by X-ray Fluorescence and different rocks were heated in a microwave heating unit. The results showed that the relationship between the temperature and heating time is exponential and depends on the rock oxide contents. It was found that the iron oxides may be unstable at microwave and rocks with high levels of magnesium oxides and sulfates tend to be good absorbers of microwave. Rocks containing high levels of calcium, silicon, titanium, barium and chloride (NaCl) are not good absorbers of microwave. It was also noted that faster solid heating, lesser the efficiency of microwave drying.

The Effects of Glass Bubbles, Clay, Xanthan Gum and Starch Concentrations on the Density of Lightweight Biopolymer Drilling Fluid

2014 ◽  
Vol 625 ◽  
pp. 526-529 ◽  
Author(s):  
Lim Symm Nee ◽  
Badrul Mohamed Jan ◽  
Brahim Si Ali ◽  
Ishenny Mohd Noor
Keyword(s):  
Xanthan Gum ◽  
Oil And Gas ◽  
Raw Materials ◽  
Drilling Fluid ◽  
Oil And Gas Industry ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Hydrocarbon Production ◽  
Water Based ◽  
Environmentally Safe

It is an open secret that currently oil and gas industry is focusing on increasing hydrocarbon production through underbalanced drilling (UBD) and finding ways to ensure the drilling process is less harmful to the environment. Water-based biopolymer drilling fluids are preferred compared to oil based drilling fluids owing to the fact that it causes less pollution to the environment. This paper investigates the effects of varying concentrations of environmentally safe raw materials, namely glass bubbles, clay, xanthan gum and starch concentrations on the density of the formulated biopolymer drilling fluid to ensure that it is suitable for UBD. As material concentrations were varied, the density for each sample was measured at ambient temperature and pressure. Results showed that the final fluid densities are within acceptable values for UBD (6.78 to 6.86 lb/gal). It is concluded that the formulated water-based biopolymer drilling fluid is suitable to be used in UBD operation.

scholarly journals Lubricating Properties of Water-Based Drilling Fluid Improvement Using Lignite NPs as well as Their Effect on Rheological and Filtration Properties

2019 ◽  
Vol 26 (1) ◽  
pp. 81-88
Author(s):  
Massara Salam ◽  
Nada S. Al-Zubaidi ◽  
Asawer A. Al-Wasiti
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Drill String ◽  
Filter Press ◽  
Drilling Fluids ◽  
Well Drilling ◽  
Water Based ◽  
Frictional Forces ◽  
Filtration Properties ◽  
Lubricating Properties

In the process of drilling directional, extended-reach, and horizontal wells, the frictional forces between the drill string and the wellbore or casing can cause severe problems including excessive torque which is one of the most important problems during drilling oil and gas well. Drilling fluid plays an important role by reducing these frictional forces. In this research, an enhancement of lubricating properties of drilling fluids was fundamentally examined by adding Lignite NPs into the water-based drilling fluid. Lubricity, Rheology and filtration properties of water-based drilling fluid were measured at room temperature using OFITE EP and Lubricity Tester, OFITE Model 900 Viscometer, and OFITE Low-Pressure Filter Press, respectively. Lignite NPs were added at different concentrations (0.05 %, 0.1 %, 0.2 %, 0.5 %, and 1 %) by weight into water-based drilling fluid. Lignite NPs showed good reduction in COF of water-based drilling fluid. The enhancement was increased with increasing Lignite NPs concentrations; 23.68%, 35.52%, and 45.3 % reduction in COF were obtained by adding 0.2%, 0.5%, and 1% by weight Lignite NPs concentration, respectively.

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