Evaluation of Hydraulic Fracturing Models and Their Limitations to Predict No-Drill Zones for Horizontal Directional Drilling

2018 ◽  
Author(s):  
Saeed Delara ◽  
Kendra MacKay
Keyword(s):  
Hydraulic Fracturing ◽  
Safety Factor ◽  
Standard Procedure ◽  
Accurate Determination ◽  
Strength Properties ◽  
Analytical Models ◽  
Alternative Methods ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
The Impact

Horizontal directional drilling (HDD) has become the preferred method for trenchless pipeline installations. Drilling pressures must be limited and a “no-drill zone” determined to avoid exceeding the strength of surrounding soil and rock. The currently accepted industry method of calculating hydraulic fracturing limiting pressure with application of an arbitrary safety factor contains several assumptions that are often not applicable to specific ground conditions. There is also no standard procedure for safety factor determination, resulting in detrimental impacts on drilling operations. This paper provides an analysis of the standard methods and proposes two alternative analytical models to more accurately determine the hydraulic fracture point and acceptable drilling pressure. These alternative methods provide greater understanding of the interaction between the drilling pressures and the surrounding ground strength properties. This allows for more accurate determination of horizontal directional drilling limitations. A comparison is presented to determine the differences in characteristics and assumptions for each model. The impact of specific soil properties and factors is investigated by means of a sensitivity analysis to determine the most critical soil information for each model.

scholarly journals Installation of submarine cables and pipes in shallow waters and connecting them to the shore by the method of horizontal directional drilling

2021 ◽  
Vol 286 ◽  
pp. 04007
Author(s):  
Valeriu-Florian Vasilescu ◽  
Dumitru Dinu
Keyword(s):  
Marine Environment ◽  
Offshore Wind ◽  
Shallow Waters ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Negative Effects ◽  
Subsea Tunnel ◽  
Submarine Cables ◽  
Wind Energy Systems ◽  
The Impact

This article presents the horizontal directional drilling (HDD) as one of the most suitable technique used to reduce the impact on the environment during the submarine pipe and cable installation process, especially in the coastal area and shallow waters. HDD is a technique used to drill a subsea tunnel or under other designated area with the goal to pull a pipe or other facility through the drilled underground tunnel. With the development of the offshore natural gas and wind industry, the demand for the construction of transfer pipeline and cables has also increased. The installation of submarine pipelines and cables can have negative effects on the marine environment. This is one of the main reasons that construction and operation of offshore wind energy systems has been and continues to be regarded with scepticism by environmental activists, despite the undeniable benefits of this renewable energy source. The main objectives of this article are to emphasize the importance of using this technique but also to highlight the benefits, in particular by significantly reducing the impact on the marine environment.

Modeling of Annular Pressures in Horizontal Directional Drilling

2004 ◽  
Author(s):  
Samuel T. Ariaratnam ◽  
Richard Stauber ◽  
Bruce Harbin
Keyword(s):  
Hydraulic Fracturing ◽  
Drilling Fluid ◽  
Pressure Effects ◽  
Soil Conditions ◽  
Drilling Fluids ◽  
Fluid Composition ◽  
Directional Drilling ◽  
Limited Information ◽  
Horizontal Directional Drilling ◽  
Wide Range

Horizontal Directional Drilling (HDD) is an established trenchless construction method for the installation of underground utilities and pipelines. Subsequently, the method is becoming widely accepted as a cost-effective alternative to traditional open-cut construction. However, the occurrence of hydraulic fracturing, resulting in the migration of drilling fluid to the surface has placed the HDD process under scrutiny, especially when being considered for environmentally sensitive projects. Hydraulic fracturing results from an excess buildup of fluidic pressure within the borehole. Models have been developed to predict borehole pressures; however, there is limited information available on the relationship between drilling returns and fluid composition to these pressures. A research program was undertaken to model and determine flow characteristics for drilling returns under a variety of soil conditions and bore penetration rates. Nine soil samples were gathered based on the Unified Soil Classification System (USCS) and their respective rheological properties were obtained for different drilling fluids and target slurry densities. This paper presents, as an example, a comparison and analysis of the predicted borehole pressures of clayey-sand (SC) soil in a large directional drill rig application and provides recommendations for contractors when attempting installations in various geological formations. The pressure effects of pipe eccentricity within a borehole were analyzed using a computer model. The result of this research is a simplified approach for predicting downhole fluid pressures for a wide range of project parameters that can be used as a guide to minimize the occurrence of hydraulic fracturing.

The Impact of Risk in Horizontal Directional Drilling

2012 ◽  
Author(s):  
Manley Osbak ◽  
Alireza Bayat ◽  
Carrie Murray
Keyword(s):  
Risk Mitigation ◽  
Risk Index ◽  
Business Case ◽  
Quantitative Information ◽  
Mitigation Measures ◽  
Directional Drilling ◽  
Information Industry ◽  
Project Schedule ◽  
Horizontal Directional Drilling ◽  
The Impact

The risks, associated with horizontal directional drilling (HDD) can have a significant impact on project schedule and cost. Contractors, engineers and owners are generally aware of the potential impact of this risk, but the awareness is largely qualitative in nature, and is thereby limiting for pointed decision making and the development of measured risk mitigation. Without quantitative information, industry stakeholders are without the means to evaluate risk strategies and identify appropriate risk mitigation measures in a manner that adequately develops and supports the business case for risk mitigation. As a result, the industry often has little choice other than to resort to accepting the risk and hoping for the best or transferring the risk using contractual methods. In order to move to a position of active assessment and mitigation, the industry needs quantitative information about the overall impact of risk as well as a comprehensive enumeration of risk events, the probability of occurrence and the impact of individual events. This paper looks at the general impact of risk as has occurred on 100 medium and large HDD projects. The general impact, in terms of schedule (and by extension, cost), serves to illuminate the need for structured risk mitigation. The paper also lists the risk events that have occurred on these 100 projects, as well as the frequency of occurrence, the average schedule impact and the Risk Index of each event type.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

EMERGENCY RESPONSE IN THE PIPELINE CONSTRUCTION BY HORIZONTAL DIRECTIONAL DRILLING

2015 ◽  
pp. 91-96
Author(s):  
I. E. Kiryanov ◽  
Yu. D. Zemenkov ◽  
S. M. Dorofeev ◽  
V. S. Toropov
Keyword(s):  
Emergency Response ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Pipeline Construction ◽  
Trenchless Construction

On the basis of analyzing the characteristics of used materials and the parameters of trenchless transitions profiles was developed emergency response, including several schemes of release a pipe jammed in the hole during the pipeline pulling in the pipeline construction by horizontal directional drilling. Proposed schemes applicability analyzed for trenchless construction real conditions.

scholarly journals From the Vector to Scalar Perturbations Addition in the Stark Broadening Theory of Spectral Lines

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 176
Author(s):  
Valery Astapenko ◽  
Andrei Letunov ◽  
Valery Lisitsa
Keyword(s):  
Spectral Line ◽  
Stark Effect ◽  
Coulomb Field ◽  
Spectral Lines ◽  
Alternative Methods ◽  
Scalar Perturbation ◽  
Numerical Comparison ◽  
Line Shapes ◽  
Stark Effects ◽  
The Impact

The effect of plasma Coulomb microfied dynamics on spectral line shapes is under consideration. The analytical solution of the problem is unachievable with famous Chandrasekhar–Von-Neumann results up to the present time. The alternative methods are connected with modeling of a real ion Coulomb field dynamics by approximate models. One of the most accurate theories of ions dynamics effect on line shapes in plasmas is the Frequency Fluctuation Model (FFM) tested by the comparison with plasma microfield numerical simulations. The goal of the present paper is to make a detailed comparison of the FFM results with analytical ones for the linear and quadratic Stark effects in different limiting cases. The main problem is connected with perturbation additions laws known to be vector for small particle velocities (static line shapes) and scalar for large velocities (the impact limit). The general solutions for line shapes known in the frame of scalar perturbation additions are used to test the FFM procedure. The difference between “scalar” and “vector” models is demonstrated both for linear and quadratic Stark effects. It is shown that correct transition from static to impact limits for linear Stark-effect needs in account of the dependence of electric field jumping frequency in FFM on the field strengths. However, the constant jumping frequency is quite satisfactory for description of the quadratic Stark-effect. The detailed numerical comparison for spectral line shapes in the frame of both scalar and vector perturbation additions with and without jumping frequency field dependence for the linear and quadratic Stark effects is presented.

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