Drill Column Research Articles

Сызықтық және сызықтық емес қасиеттерді ескере отырып бұрғылау бағанның тербелістерін модельдеу

The purpose of the work is to develop and analyze linear and nonlinear mathematical models of the dynamics of drilling columns and their combinations, complicated by external loads and environmental factors. The object of study is the oscillation of a loaded drilling column, which is used for drilling oil and gas wells when interacting with the environment. The practical significance of mathematical models of oscillations of the drill column lies in the detailed description of oscillatory phenomena that occur directly during the drilling of oil and gas wells, and in the analysis of the influence of geometric and mechanical parameters of the drill column, external loads on its oscillations to prevent curvature.

Design and Simulation Analysis of Semi-Active Lifting and Sinking Compensation System

The lifting and sinking motion generated by the drilling platform causes large fluctuations in the suspension tension of the large hook, which affects the stability of the drilling pressure acting on the rock at the bottom of the well, greatly reduces the efficiency of drilling and decreases the service life of the drill bit and the drill column under the action of cyclically varying loads, causing an increase in the overall drilling cost. In order to avoid the above situation, a nonlinear model of a semi-active lift-sink compensation system is designed and a method to improve the compensation efficiency of the system is proposed. Firstly, the relevant physical model of the hydraulic system is established, and then its simulation model is built according to the working principle of the semi-active lift and sink compensation system. Then the effects of different factors are added to the simulation model of semi-active lifting and sinking compensation, and finally the effects of different factors on the compensation efficiency of the active lifting and sinking system are compared. The simulation results show that a regular sinusoidal wave with a peak value of 6.5 m and a period of 10 s as the ship's lifting and sinking displacement input will reduce the compensation efficiency of the semi-active lifting and sinking compensation system, while the smaller the stiffness of the wire rope, the better the compensation effect of the drill column and the higher the compensation accuracy. The proposed method can effectively improve the compensation efficiency of semi-active lifting and sinking compensation system.

Обоснование альтернативной конструкции скважин (на примере Среднеботуобинского нефтегазоконденсатного месторождения)

The circulation loss in well construction is one of the most frequent troubles at the Srednebotuobinsky oil and gas condensate field (SBOGCF). Such problems occur in the two basic intervals of the geological section, trapp intrusion and the Botuobinsky productive horizon. The intervals of salts, endogenic fracturing spread in the intrusive sheet, and gas-bearing collectors with abnormally high formation pressure, available in the SBOGCF, are currently considered incompatible drilling conditions. The emergency time, spent for fighting these issues within the trap intrusion interval, may reach 42 days per well. However, the loss of working time is not the only trouble; costs of drill fluids and cement grouts as well as of concomitant emergencies (striking of the drill column bottom arrangements) result in the increasing costs of well construction as well as to the lost advantage due to the late launching of the well. One of the ways to decrease the well construction cycle is reconsidering the existing design and adapting a brand new approach to drilling and well construction, which would permit to use the alternative well design for solving the abovementioned problems.

A transfer learning-based digital twin for detecting localised torsional friction in deviated wells

Digital twins seek to replicate a physical structure in a digital domain. For a digital twin to have close correspondence to its physical twin, data are required. However, it is not always possible, or cost-effective, to collect a complete set of data for a structure in all configurations of interest. It is nonetheless useful to repurpose data to help validate predictions for different configurations and scenarios. This statement is true in drilling applications, where, for example, the length of the drill string is altered throughout operation. This paper demonstrates how transfer learning, in the form of three domain-adaptation methods, — transfer component analysis (TCA), maximum independence domain adaptation (MIDA) and geodesic flow kernel (GFK) — can be used to construct a digital twin for localising torsional friction in deviated wells under structural changes (e.g., when the drill column gets longer). The method uses a physics-based torsional model to train a machine-learning classifier that can localise torsional friction for a given drill string length and diameter, where friction localisation labels are known (source). As the length or diameter of the drill string are altered in the field, transfer learning is utilised to map the classifier from the labelled (source) scenario onto these unlabelled (target) scenarios. As a result, transfer learning improves the performance of the classifier when applied to the target data, and increases the domain of validity for the classifier. The performance of the classifier, and therefore its suitability to new drill-string configurations, is estimated by utilising two different distance metrics between the source and a proposed target dataset.

Differential self-adapting drilling machine with three degrees of freedom

A critical factor for engineering progress both in surface and underground mining of extremely hard minerals is the expensive and labor-hungry process of drilling. A top priority task is to create highproduction and energy-efficient drill rigs. It is only possible to improve greatly the drilling process performance through automation of the drilling machine mechanisms which effect the drill column with certain force and kinematic parameters to implement a certain mode of drilling. Actually, the rotary percussive drill rigs mostly possess three mutually independent dynamic systems—axial drive, rotary drive and percussion mechanism. These systems never coordinate their drive signals with the drill column response when interacting with rock mass, which leads to overloads, unwanted vibrations and other adverse effects. Improvement of productivity and energy efficiency of drill rigs is impossible without automation. This article examines the mechanism of a differential self-adapting rotary percussive drilling machine with programmable drilling mode control. The mechanism and its operation are extensively described. The proposed layout of the differential self-adapting drilling machine with three degrees of freedom, with feedback between the drilling column and the axial drive, rotary drive and percussion mechanism toward the automated control of the feed force and velocity, as well as the impact energy and frequency, enables neutralization of adverse effects in rotary percussion drilling.

Influence of bit size on stability bottom drill column balance when drilling a horizontal well

The article raises the question that if you change the bit type, the "critical length" of the lower part of the drill string change too. For the first time, the issue of the stability of the lower part of the drill string when drilling a horizontal section of the wellbore was formulated and solved, taking into account the features of the bit designs (roller bit, wing bit, PDC bit) and the mechanism of rock destruction in well drilling. The research uses the generally accepted provisions of the linear theory of elasticity of materials, the theory of stability of rods and shells. It is assumed that the lower part of the drill string is a heavy elastic rod, experiencing the combined action of the forces of the pipe's own weight and the axial load on the bit, and the twisting moment from the rotor table acting on the pipe string is not taken into account. To find the "critical length" of the lower part of the drill string, simple approximate formulas are obtained that take into account the bit size, drill collar and axial load.

ПРУЖНЕ ЗГИНАННЯ БУРИЛЬНОЇ КОЛОНИ В ЕЛІПТИЧНІЙ СВЕРДЛОВИНІ З ГЕОМЕТРИЧНИМИ НЕДОСКОНАЛОСТЯМИ

The problem is posed of determining the resistance forces and internal forces in the drill string during drilling and when performing tripping operations in a curved well. The object of the study is the geometry of the centerline of deep inclined well trajectories. The aim of the work is to formulate and solve new problems of structural mechanics about nonlinear deformation of drill strings in directional wells. To study the mechanics of elastic bending of drill strings in directional wells, the methods of structural mechanics of flexible curved rods were used; methods of differential geometry and theory of surfaces; numerical Runge-Kutta method. The study of the influence of geometric imperfections of the borehole centerline on the forces of contact interaction between the drill string and the borehole wall has been carried out. The case is considered when geometric imperfections have the form of a localized spiral of variable radius. KEY WORDS: OIL AND GAS WELLS, CURVED TRAJECTORY, DRILLING COLUMN, RESISTANCE FORCES.

The maximum achievable level of error in measuring the mechanical drilling speed

The article is devoted to the problem of mechanical velocity measurement in deep wells. The standard error limit is set at 2,5 %. However, the existing methods of measurement of drilling parameters have large errors associated with the presence of friction forces in the well, temperature changes with depth, column layout, etc. The error is also introduced by the discrete measurement method, which manifests itself in smoothing of the useful signal and delay in the information about the speed value by half the averaging interval. The aim of the work is to determine the realistically achievable values of the mechanical drilling speed. For this, the reduced error was calculated according to the upper limit of measurement in accordance with GOST. The dependence of the error on the depth of the well and the drilling speed is graphically presented. The error estimation for different type of drilling and different column layout is given. The analysis of the obtained results showed that the set value of the error can be achieved not in the entire range of changes in the speed and depth of the well bottom.

Determination of the Specific Fracture Energy of the Material under Shear Deformation

We present a procedure for the evaluation of the strain and fracture energy of the material under the conditions of shear deformation based on the application of the method of digital image correlation. The established characteristics are used to determine the stress-strain state and service life of drill columns and shafts of hydraulic turbine in bending and torsion.

ПРОГНОЗУВАННЯ ПОВЕДІНКИ ДИСПЕРСНОГО ГРУНТУ В ОСНОВАХ БУРОВИХ ОПОР-КОЛОН ЗА МГЕ

At present, the construction of frame buildings is carried out on ordinary pillar foundations, the device of which is associated with the need to carry out a large amount of excavation, significant costs for the manufacture of formwork and preparation of concrete mix in cramped conditions. Reduced labor costs and savings can be obtained by using foundations from bored piles and the installation of reinforced concrete grouting, and this also requires fragments of pits, additional outlets of reinforcement, waste of materials. In addition, concreting of grillages with a technological break after the installation of piles increases the construction time. More economical is the use of single drill support columns. They have a larger trunk diameter than brown stuffed piles and higher bearing capacity. The extensions at the top of the trunk increase the ground resistance in the horizontal direction due to the developed lateral surface, and also favors the use of vertical loading to load the vipore prism, which is adjacent to the upper part of the support (by analogy with pyramidal piles). Expanded plate raises the bearing capacity on the ground to the effect of vertical loading. The increase in industrial and civil construction and the need to design reliable and economical structures require the development of modern forecasting methods for determining the bearing capacity of this type of foundations in order to ensure the strength of structures. The development and implementation of more advanced and economical methods of calculating and designing foundation structures aimed at the development and implementation of their reserves is an important and relevant problem of building science. Taking into account the nonlinearity of the deformation of foundations in conjunction with the principles of their optimal design allows us to increase the adequacy of the calculations and obtain a significant economy of concrete and reinforcement. In the work on the numerical method of boundary elements (SEM) from the positions of the mechanics of a dispersed elasto-plastic medium, the concepts of predicting the bearing capacity of drill columns with extensions in the upper and lower parts are laid out. The solution of the nonlinear problem of predicting the bearing capacity of drill-pillars with extensions is of both scientific and practical importance and is directly related to the analysis of the ground VAT.

Technological potential of impact vibration damper of drill string with discrete working medium

The article discusses issues related to vibrations of drilling string bottom layout during construction of oil and gas wells. Analysis of causes of longitudinal vibrations occurring during rotary drilling is carried out. Invention proposes using vibration dampers of impact principle of action using discrete working medium. We described a device of this type of vibration dampers for drill columns. A probabilistic model of shock vibration damper operation with discrete operating medium is given. Analysis of the model shows the efficiency of using these types of vibration dampers to eliminate high-amplitude vibrations of drill columns.

Vibration damper-calibrator for shock wave damping from sharp bit installation on the bottomhole

This article addresses the problem of drill string vibration. In particular, the issue of quenching of high-amplitude low-frequency vibrations generated from sharp installation of the bit on the bottomhole is analyzed. This problem is virtually uncontrolled and arises from objective factors such as rock collapse and subjective factors such as driller error. It is proposed to use impact type of vibration damper for damping of this type of vibration. Possible design of well impact vibration damper-calibrator is shown. A dynamic model of the vibration damper has been built. Analysis of the model suggests the efficiency of using these types of vibration dampers to eliminate high-amplitude low-frequency vibrations of drill columns.

Інтегральні показники зміни вібрації бурильної колони — критерій оцінки зношеності шарошкового долота

Інтегральні показники зміни вібрації бурильної колони — критерій оцінки зношеності шарошкового долота

Вихретоковый неразрушающий контроль конической замковой резьбы элементов бурильных колонн

Вихретоковый неразрушающий контроль конической замковой резьбы элементов бурильных колонн

НАУКОВІ ТЕНДЕНЦІЇ БУРІННЯ ГЛИБОКИХ НАФТОГАЗОВИХ СВЕРДЛОВИН


 
 
 The essential problems in oil and gas industry are corrosion-fatigue breakage of drill column elements, sticking of drilling and heavy-weight drill pipes, taking place in drilling of directional and horizontal wells. The stickings are caused by friction, emerging between sides of hole and elements of drilling column. The frictions block assurance of core integrity in core receive. The failure resistance by using polymer and composite materials for surface treatment under influence of triboprocess and corrosion-fatigue breakage is considered in the article.The problem of deep well drilling is considered, which is connected with the prevention of the seizure phenomenon between the walls of the drill column and the barrel of deep wells. The design of the coupling connection of casing pipes with a high pressure sealing element is provided to provide the tightness of the casing columns at high pressure and temperature parameters. The elastically deformed state of the pipes with the inserted sealing element is scientifically substantiated.
 
 

Influence of additives on the friction and wear reduction of oil-based drilling fluid

In comparison to conventional vertical hole drilling, extended reach drilling wells with long horizontal section require higher driving torque due to the increased drag on the drill string, drill column, casing and other equipment. This has led to higher friction and wear on the drilling equipment. Friction and wear preventive properties of oil-based drilling fluid is therefore important to keep oil extraction economical and sustainable. The addition of small concentrations of hydrocarbon additives to drilling fluid has shown significant positive effects on these properties. In this study, improvements in friction and wear properties of drilling fluid with the use of friction reduction additives was analyzed using a four-ball experimental configuration. Experiments resulted in wear in boundary and mixed lubrication regimes due to significant metal-metal interaction. The results showed that liquid friction reduction additives with long hydrocarbon tails and high metal affinity polar heads achieved better performance than additives that contained molybdenum dialkyldithiocarbamate. Energy dispersive spectroscopy results indicated lower levels of salts and corrosive chemicals on the surface of the wear scars for the best preforming additives.

ЗАЛЕЖНІСТЬ МЕХАНІЧНОЇ ШВИДКОСТІ БУРІННЯ СВЕРДЛОВИН ВІД ВНУТРІШНЬОПОРОВОГО ТИСКУ РОЗКРИТИХ ПОРІД У ПЕРЕДКАРПАТСЬКОМУ ПРОГИНІ

The paper considers the dependence of the mechanical speed of wells drilling on the seams with abnormally high spatial (reservoir) pressures. Forecasting of AHRP is important for improving the degree of completion of layers in process of drilling. As a result of the drilling in of unpredictable areas of AHRP in the Pre-Carpathian region the drill columns often get stuck, one of the reasons for which is not often a justified preventive weighting of the drilling mud. To regulate the pressure in the well during drilling, it is necessary to identify the upper limit of the AHRP zone in time and give it a reasonably quantified characteristics. After analysying the data of wells in the Pre-Carpathian region and those that are being drilled now, it was possible for us to establish that in the case of approaching the well bore to the formation of AHRP, there is an increase in the mechanical speed of drilling in clay rocks, due to the presence of increased inernal pressure and a lower density of these rocks. Increasing of the mechanical speed of drilling under the condition of constant parameters of the drilling regime is also due to heterogeneity of rocks, and stratigraphic transitions from one fold to the other. However, in the case of a double increase of the mechanical speed of drilling in sedimentary layers which are identical in lithology, it is possible to confidently explain this phenomenon by the entrance of the borehole into the AHRP zone. In order to verify the possibility of using mechanical logging to predict the areas of AHRP directly during drilling, we compared the change in the mechanical speed of drilling along the well bore with the data of quantitative and qualitative determination of the areas of AHRP on the results of industrial-geophysical research. Qualitative and quantitative estimation of AHRP zones was carried out, basically, according to the data of electrometry of wells, using the technique of "curves of normally densified clay". For the verification of the findings, direct measurements of the formation pressure with the pressure gauges were used and the data of determination of the formation pressures in the case of transfer of clay solution from the well. Due to the prediction of spatial and reservoir pressures by means of mechanical logging in the process of well laying, we observe a decrease in accidents rate, and an increase in the efficiency of drilling.

Drilling performance analysis of drill column machine using proposed neural networks

In spite of advanced material cutting technology, there are still some problems due to unpredicted vibrations on horizontal and vertical directions on column drilling machines. This paper presents an investigation for drilling condition of drill column machines performance using proposed neural networks. The investigation is divided into two parts. First, the drill column machine is employed to analyze vibrations with steel and aluminum materials for increased drilling speeds. During the working of the system, some measuring points are indicated to analyses of drilling conditions. Finally, two types of proposed neural networks predictors are used to predict vibration variation for both cases of steel and aluminum materials of drilling systems. The experimental and simulation result is improved that radial basis neural network has superior performance to adapt experimental applications for drill column machines.

Ionic composition of pore water in shallow shelf deposits of the Laptev Sea

The cationic and anionic compositions of pore water in shallow deposits of Buor-Khaya Bay is studied. Significant concentration heterogeneity of the vertical ionic profile in the studied drill columns is shown. It is established that the vertical ionic profile of shelf deposits of the Laptev Sea is basically formed under the influence of thawing of underwater permafrost, hydrodynamic conditions, the water mass, and heat flows and depends on the lithological and granulometric types of the deposits. The highest concentrations of ions are registered in plant detritus represented by ground grass vegetation. A relationship between the ionic composition of pore water and cryogenic state of the sequence and its variability is demonstrated using the method of major components.

Numerical analysis of nonlinear oscillatory processes in columns at drilling oil and gas well

The paper describes the behavior of the system of geometrically nonlinear drill columns under the action of dynamic loads. The authors used the finite element method to solve the boundary value problems. The forms of the beam in the transverse direction were expressed by cubic Hermite polynomials. It has been found out that nonlinearity of the column may substantially change the character of oscillatory processes in its transverse direction. The loss of stability may occur during slip kicking at high values of nonlinearity.