New Hybrid Hole Cleaning Model for Vertical and Deviated Wells

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Ahmed Abdulhamid Mahmoud ◽  
Mahmoud Elzenary ◽  
Salaheldin Elkatatny
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Real Field ◽  
Oil Well ◽  
Hole Size ◽  
Drilling Mud ◽  
Rate Of Penetration ◽  
Hole Cleaning ◽  
Fluid Rheology ◽  
Pipe Size

Abstract Drilled cuttings transportation from the bottom hole to the surface to maintain efficient hole cleaning is a challenging issue while drilling vertical, deviated, high angle, and extended reach wells. This is attributed to the huge number of the parameters affecting the ability of the drilling fluid to leave the drilled solids. Drilling fluid rheology, density, and flowrate, hole size, drill pipe size, hole inclination, and rate of penetration are all confirmed experimentally to affect the effectiveness of the drilling mud to lift the fluid and keep a clean hole. Several parameters were developed earlier to account for the hole cleaning conditions, most of these parameters lake to including many of the parameters influencing the hole cleaning conditions. In this study, a new hole cleaning parameter was developed, which is called hole cleaning factor (HCF). The HCF parameter was developed based on the cutting carrying index (CCI) parameter, and it considered the effect of the drilling fluid rheology, density, and flowrate, the hole size, drill pipe size, hole inclination, and rate of penetration to identify the hole cleaning condition. The HCF model was applied in an oil well from North Africa to predict the hole cleaning condition at different 135 points where the depth ranges from 33 to 12,854 ft. The outcomes of the HCF were well correlated with the real-field scenarios, where the crew members faced by erratic torque with differentiation in drilling parameters resulting in worst stuck pipe conditions at the same depths as predicted by the HCF parameter. The developed HCF model will help the drilling engineers to avoid many issues while drilling such as cutting accumulation and drill pipe sticking. The predictability of the HCF model was compared with commercially available software, and the results indicated a good match between the predictability of the HCF model and the commercial software.

Comprehensive experimental investigation of hole cleaning performance in horizontal wells including the effects of drillstring eccentricity, pipe rotation and cuttings size

2021 ◽  
pp. 1-11
Author(s):  
Ahmed K. Abbas ◽  
Mortadha T. Alsaba ◽  
Mohammed F. Al Dushaishi
Keyword(s):  
Flow Rate ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Real Field ◽  
Operational Parameters ◽  
Cleaning Efficiency ◽  
Hole Cleaning ◽  
Cleaning Performance ◽  
Pipe Rotation

Abstract Extended reach (ERD) wells with a horizontal and highly deviated section are widely applied in the oil and gas industry because they provide higher drainage area than vertical wells; and hence, increase the productivity or injectivity of the well. Among many issues encountered in a complex well trajectory, poor hole cleaning is the most common problem, which occurs mainly in the deviated and horizontal section of oil and gas wells. There are significant parameters that have a serious impact on hole cleaning performance in high-angle and horizontal sections. These include flow rate, rheology and density of the drilling fluid, drillstring eccentricity, pipe rotation, and cuttings size. It has been recognized that the action of most of these parameters to transport drilled cuttings is constantly a point of controversy among oilfield engineers. In the present study, extensive experiments were conducted in an advanced purpose-built flow rig to identify the main parameters affecting on circulate the cuttings out of the test section in a horizontal position. The flow-loop simulator has been designed to allow easy variation of operational parameters in terms of flow rate, mud density, drillstring eccentricity, pipe rotation, and cuttings size. In addition, the study covers the impacts of laminar, transition, and turbulent flow regimes. The goal of such variation in the operational conditions is to simulate real field situations. The results have shown that drill string rotation and flow rate were the operational parameters with the highest positive influence on the cuttings transports process. In contrast, drill pipe eccentricity has a negative influence on cuttings removal efficiency. The cuttings transportation performance is further improved by pipe rotation at different levels of eccentricity, especially at fully eccentric annuli. It was also shown that larger cuttings appeared to be easier to remove in a horizontal annulus than smaller ones. The experimental results would provide a more in-depth understanding of the relationship between drilling operation parameters and hole cleaning efficiency in ERD operations. This will help the drilling teams to realize what action is better to take for efficient cutting transportation.

scholarly journals The effect of drill–pipe rotation on improving hole cleaning using polypropylene beads in water-based mud at different hole angles

2019 ◽  
Vol 10 (3) ◽  
pp. 1253-1262 ◽  
Author(s):  
A. Katende ◽  
B. Segar ◽  
I. Ismail ◽  
F. Sagala ◽  
H. H. A. R. Saadiah ◽  
...  
Keyword(s):  
Buoyancy Force ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Drilling Mud ◽  
Hole Cleaning ◽  
Drag Forces ◽  
Water Based ◽  
Drilling Operations ◽  
Cost Efficient ◽  
Pipe Rotation

AbstractHole cleaning is always a problem, particularly during drilling operations, and drilling fluid plays an important role in transporting drill cuttings through an annular section of wellbore to the surface. To transport the cuttings, a water-based mud with added polypropylene beads was selected since it is environmentally friendly and cost efficient. The polypropylene beads help to transport cuttings by providing an additional buoyancy force that lifts the cuttings to the surface via the influence of collision and drag forces. This experiment was performed using a 20 ft test section, 10 ppg drilling mud and 0.86 m/s annular velocity in a laboratory scale rig simulator, and the concentration of polypropylene beads was varied from 0 to 8 ppb. As the concentration of polypropylene increases, the cutting transport ratio also increases. It was observed that the fewest cuttings are lifted at a critical angle of 60°, followed by 45°, 30°, 90° and 0°. Additionally, cutting sizes had moderate effects on the cutting lifting efficiency, where smaller cutting sizes (0.5–1.0 mm) are easier to lift than larger cutting sizes (2.0–2.8 mm). Furthermore, a study of buoyancy force and impulsive force was conducted to investigate the cutting lifting efficiencies of various concentrations of polypropylene beads. This lifting capacity was also assisted by the presence of polyanionic cellulose (PAC), which increases the mud carrying capacity and is effective for smaller cuttings. The results show that in the presence of pipe rotation, the cutting lifting efficiency is slightly enhanced due to the orbital motion provided by the drill pipe for better hole cleaning. In conclusion, polypropylene beads combined with pipe rotation increase the cutting transport ratio in the wellbore.

Pipe stick problems of deep well drilling

2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Differential Pressure ◽  
Drilling Mud ◽  
Fluid Circulation ◽  
Well Drilling ◽  
Deep Well ◽  
Pressure Pipe ◽  
Bottomhole Pressure

The aricle is about the pipe stick problems of deep well drilling. Pipe stick problem is one of the drilling problems. There are two types of pipe stick problems exist. One of them is differential pressure pipe sticking. Another one of them is mechanical pipe sticking. There are a lot of reasons for pipe stick problems. Indigators of differential pressure sticking are increase in torque and drug forces, inability to reciprocate drill string and uninterrupted drilling fluid circulation. Key words: pipe stick, mecanical pipe stick,difference of pressure, drill pipe, drilling mud, bottomhole pressure, formation pressure

Scaling Formulae for the Wellbore Hydraulics Similitude with Drill Pipe Rotation and Eccentricity

2021 ◽  
Author(s):  
Thad Nosar ◽  
Pooya Khodaparast ◽  
Wei Zhang ◽  
Amin Mehrabian
Keyword(s):  
Power Law ◽  
Flow Rate ◽  
Annular Flow ◽  
Rotation Speed ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Flow Loop ◽  
Annular Flows ◽  
Fluid Rheology ◽  
Pipe Rotation

Abstract Equivalent circulation density of the fluid circulation system in drilling rigs is determined by the frictional pressure losses in the wellbore annulus. Flow loop experiments are commonly used to simulate the annular wellbore hydraulics in the laboratory. However, proper scaling of the experiment design parameters including the drill pipe rotation and eccentricity has been a weak link in the literature. Our study uses the similarity laws and dimensional analysis to obtain a complete set of scaling formulae that would relate the pressure loss gradients of annular flows at the laboratory and wellbore scales while considering the effects of inner pipe rotation and eccentricity. Dimensional analysis is conducted for commonly encountered types of drilling fluid rheology, namely, Newtonian, power-law, and yield power-law. Appropriate dimensionless groups of the involved variables are developed to characterize fluid flow in an eccentric annulus with a rotating inner pipe. Characteristic shear strain rate at the pipe walls is obtained from the characteristic velocity and length scale of the considered annular flow. The relation between lab-scale and wellbore scale variables are obtained by imposing the geometric, kinematic, and dynamic similarities between the laboratory flow loop and wellbore annular flows. The outcomes of the considered scaling scheme is expressed in terms of closed-form formulae that would determine the flow rate and inner pipe rotation speed of the laboratory experiments in terms of the wellbore flow rate and drill pipe rotation speed, as well as other parameters of the problem, in such a way that the resulting Fanning friction factors of the laboratory and wellbore-scale annular flows become identical. Findings suggest that the appropriate value for lab flow rate and pipe rotation speed are linearly related to those of the field condition for all fluid types. The length ratio, density ratio, consistency index ratio, and power index determine the proportionality constant. Attaining complete similarity between the similitude and wellbore-scale annular flow may require the fluid rheology of the lab experiments to be different from the drilling fluid. The expressions of lab flow rate and rotational speed for the yield power-law fluid are identical to those of the power-law fluid case, provided that the yield stress of the lab fluid is constrained to a proper value.

scholarly journals Optimization of Hole Cleaning and Cuttings Removal in High Inclined Till Horizontal Well

2020 ◽  
Vol 21 (1) ◽  
pp. 61-66
Author(s):  
Karrar Ahmed Mohammed ◽  
Ayad A. Al-Haleem
Keyword(s):  
Flow Rate ◽  
Horizontal Well ◽  
Rolling Force ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Negative Influence ◽  
Flow Loop ◽  
Cleaning Efficiency ◽  
Hole Cleaning ◽  
Inclination Angles

The goal of this experimental study is to determine the effects of different parameters (Flow rate, cuttings density, cuttings size, and hole inclination degree) on hole cleaning efficiency. Freshwater was used as a drilling fluid in this experiment. The experiments were conducted by using flow loop consist of approximately 14 m (46 ft) long with transparent glass test section of 3m (9.84 ft.) long with 4 inches (101.6 mm) ID, the inner metal drill pipe with 2 inches (50.8 mm) OD settled with eccentric position positive 0.5. The results obtained from this study show that the hole cleanings efficiency become better with high flow rate (21 m3/hr) and it increase as the hole inclination angles increased from 60 to 90 degree due to dominated of the rolling force. The cuttings size has negative influence on cuttings recovered as size increased and that is true for all cuttings specific gravity due to direct effect of the cuttings size and density on the gravity force which work against lifting force. The increasing of hole inclination angle above 60 degree will affect positively on cuttings removal efficiency.

scholarly journals Fem stress analysis of a barrel reamer

2019 ◽  
Vol 2 (1) ◽  
pp. 178-185
Author(s):  
Attila Baksa ◽  
Gábor Ladányi ◽  
Sándor Szirbik ◽  
Zoltán Virág
Keyword(s):  
Boundary Conditions ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Small Diameter ◽  
Maximum Load ◽  
Mechanical Analysis ◽  
Oil Well ◽  
Directional Drilling ◽  
Well Drilling ◽  
Pilot Hole

Abstract Horizontal Directional Drilling (HDD) is a method of installing underground pipelines, cables and service conduit through trenchless methods. The tools and techniques used in the HDD process are an outgrowth of the oil well drilling industry, too. Installation of a pipeline by HDD is a three stages process. The first stage consists of directionally drilling a small diameter pilot hole along a designed directional path. Drilling fluid is pumped through the drill pipe to the drill bit where high pressure jets and the bit will grind the soils ahead of the drill stem. The second stage involves enlarging this pilot hole to a diameter suitable for installation of the pipeline. A reamer is pulled back and rotated while pumping drilling fluid to cut and remove solids to enlarge the hole. A kind of reamer is the subject of this paper. The final stage consists of pulling the pipeline back into the pre-reamed hole. The most important part of the mechanical analysis is to define the boundary conditions for operating situations when the tool is under maximum load. In this paper we present a helpful description for giving boundary conditions to perform the numerical simulation of a barrel reamer.

Assessment of Using Copper Nitrate for Scavenging Hydrogen Sulfide While Drilling Sour Horizontal Wells

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Salaheldin Elkatatny ◽  
Salem Basfer ◽  
Reyad Shawabkeh ◽  
Mohamed Bahgat ◽  
Mohamed Mahmoud
Keyword(s):  
Hydrogen Sulfide ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Copper Nitrate ◽  
Drilling Mud ◽  
Liquid Sulfur ◽  
Rate Behavior ◽  
Effect Of Copper ◽  
New Formulation ◽  
Very High

The solubility of hydrogen sulfide (H2S) is very high in different liquids such as water or liquid sulfur. The existence of H2S results in local corrosion and causes cracking to the steel even if the concentration of H2S is low. The objectives of this paper are to (1) evaluate copper nitrate as an H2S scavenger while drilling sour horizontal and multilateral wells and (2) investigate the effect of copper nitrate on the drilling fluid rheological properties and drill pipe corrosion. The obtained results showed that by adding the copper nitrate (1 lb/bbl) to the drilling mud there was no change in the shear stress–shear rate behavior, and the yield point (YP) plastic viscosity (PV) ratio was increased by 20% indicating good hole cleaning. In addition, the filtrate volume reduced by 26% and the filter cake thickness decreased by 50%. The new formulation of the drilling fluid with the copper nitrate is not corrosive (the corrosion rate was 0.00084 lb/ft2 after 24 h at 212 °F). Breakeven experiments showed that adding copper nitrate to the drilling fluid doubled the adsorption capacity when compared with triazine and tripled the capacity when compared with Scav1 when using I lb of the commercial H2S scavenger per bbl of the drilling fluid.

Cuttings Bed Removal in Deviated Wells

2018 ◽  
Author(s):  
Jan David Ytrehus ◽  
Bjørnar Lund ◽  
Ali Taghipour ◽  
Birgitte Ruud Kosberg ◽  
Luca Carazza ◽  
...  
Keyword(s):  
Test Section ◽  
Critical Angle ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Flow Loop ◽  
Cleaning Efficiency ◽  
Hole Cleaning ◽  
Low Viscosity ◽  
Deviated Wells

A drilling fluid for drilling deviated wellbores must provide adequate hole cleaning efficiency for all well angles relevant to the operation. For angles near vertical, experience show that hole cleaning is straight forward. In wellbore angles larger than, say, 45 degrees hole cleaning is more difficult. Cuttings beds are formed and at some well angles these beds may avalanche during circulation stops etc. This paper presents results from laboratory tests with injected cuttings using a low viscosity oil based drilling fluid with micronized grained barite as weight material. The fluid is designed for highly deviated wells with low ECD requirements and the cuttings transport performance through relevant wellbore inclinations was investigated. The experiments have been performed under realistic conditions. The flow loop includes a 10 meters long test section with 2” OD freely rotating steel drill string inside a 4” ID wellbore made of steel, representing a cased wellbore. Sand particles were injected while circulating the drilling fluid through the test section. Experiments were performed in three wellbore inclinations: 48, 60 and 90 degrees from vertical. Results show that hole cleaning in absence of drill pipe rotation is significantly improved if the well angle is less than a critical angle. This critical angle appears to be less than 60 degrees from vertical. Further result show that this critical inclination angle is dependent to the drill string rotation rate and the annular flow velocity.

APPLICATION OF MUD ANALYSIS LOGGING

Geophysics ◽  
1945 ◽  
Vol 10 (1) ◽  
pp. 76-90
Author(s):  
Robert E. Souther
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Salt Content ◽  
Gas Content ◽  
Drilling Speed ◽  
Drilling Mud ◽  
Local Conditions ◽  
Rate Of Penetration ◽  
High Salt Content ◽  
Drilling Operations

The mud analysis logging system, now widely used for exploratory and routine drilling, continuously analyzes and records the oil and gas content of mud returns from wells being drilled by the rotary method. Oil or gas detected in the returning drilling fluid indicates oil or gas in the formation penetrated by the bit. Results of the continuous analyses are instrumentally correlated to the depths and formations from which the showings originated. A second useful phase of the system plots accurately and in detail rate of penetration or drilling speed on the log as a function of depth. Trucks and trailers provide a mobile housing for all of the mud analysis equipment so that it may be moved rapidly from well to well. Applications of the method may be divided into two classes: 1. Routine drilling in proved areas where it eliminates unnecessary coring, and locates gas caps and completion zones. 2. Exploratory drilling in which it minimizes coring by indicating for testing purposes porous zones containing oil and/or gas. Mud analysis logging can be practiced in areas where the electrical log cannot be used due to high salt content or other local conditions, where dangerous hole conditions make interruption of drilling operations for coring inadvisable, and for evaluating gas zones where cores are difficult to interpret. In addition, each mud analysis logging unit contains equipment to obtain information useful in eliminating washouts, in predicting and preventing blowouts, and in controlling drilling mud characteristics.

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