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Nazarian Artur

Nazarian Artur


Faculty "Mining and Geology"

Department "Technology of Exploration Work"

Speciality "Drilling"


Improvement of technical equipment for controlling the flow of drilling fluid in the well


Scientific adviser: Artur Karakozov


Resume

Abstract on the final work:


Content

Introduction
Description of the proposed operation principle and constructive scheme
Modeling, design and development of signaling fluid circulation in the borehole
Conclusions and future research
References



Introduction


    When drilling exploration wells in the Donets Basin is often observed absorption of drilling fluid. His untimely identification can lead to content slurry in the borehole and, as a consequence – rise to complex sticking drilling tool. When drilling in the fields of coal mines, this problem is further complicated because the wells are often drilled without exiting the drilling fluid to the surface that does not give control over the process of its circulation.
    Technical basis for signaling circulation or removal of drilling fluid at present is not perfect enough, so these devices are used sporadically. At the same time, the use of such devices could solve the problem of controlling the circulation of drilling fluid in the borehole during drilling and early detection of takeovers to prevent sticking of drilling tools.
   Thus, for the practice of drilling wells in the Donets Basin is a very urgent task of improving the technical means of monitoring the flow of drilling fluid in the borehole. This will improve the technical and economic parameters of drilling by preventing accidents.

The purpose of the work – the improvement of the concept and design of control signaling the circulation of drilling fluid in the borehole and justification of its use of technology.

Research Objectives
  1. Analysis of current state of well controls the circulation of drilling fluid, or acquisitions.
  2. Improving the concept of signaling circulating drilling fluid in the borehole.
  3. Numerical modeling of signaling circulation drilling fluid in the well to determine the rational design parameters under various operating conditions.
  4. Improving the design of signaling circulating drilling fluid in the well and the technology of its application.
 Object and subject of study

   Object of study – engineering controls circulating drilling fluid in the borehole.
   Subject of research – work processes The indicator circulation drilling fluid in the borehole.

Description of the proposed operation principle and constructive scheme


   We propose the following principle of signaling device, as shown in Fig. 1. The indicator is a dynamic pressure sensor and signal element. In this case bore signaling element 2 is due to the position sensor velocity head.


Fig. 1 – Principle of signaling device

   When drilling in normal conditions (Fig. 1, a) into the drill pipe is supplied with drilling fluid flow rate Q. The liquid passes through the signaling element, in which the pressure loss is relatively small and equal DР1. Further, the liquid passes to the face, falls into the annular space and flows through the sensor velocity head. In this case, the sensor velocity head pressure drop occurs DР1с. . Further, all the drilling fluid reaches the surface.
   When drilling in the area of drilling fluid absorption (Fig. 2, b) due to the fact that not all of the liquid reaches the surface, the pressure on the sensor dynamic pressure is reduced to DР2. When the sensor changes its position, the hole in the signaling element is reduced, and the loss of pressure in it increases to DР2с. This rise in pressure is recorded on the manometer.
   Thus, the change in pressure drop across the sensor, the velocity head can be directed signaling element. On the basis of the proposed scheme (Fig. 1) developed a structural scheme of signaling device, as shown in Fig. 2, on which the patent for utility model number 50771 from 25.06.2010g [1]. His work is shown in Fig. 3.


Fig. 2 – Signaling device circulating drilling fluid in the well


Fig. 3 – Work of signaling device: a)in normal conditions; b) in the absorption of drilling fluid.

   Designed signaling device works this way. When drilling in normal conditions, the main stream of drilling fluid flowing past the throttle sleeve. With the onset of absorption of drilling fluid velocity upstream is reduced and the valve under the action of the spring moves in the down position and rests on the ledge, cutting off the radial holes in stock. The whole flow of drilling fluid begins to flow through the throttle bushing. In this case, the resistance of fluid flow in the drill pipe increases and performance gauge can be concluded about the beginning of the absorption liquid in the well.
   Similarly, signaling device triggered and the fall of liquid level in the well below its spot, because this valve 10 to completely cease to apply force from the drilling fluid in the annulus hole.


Animation principle of signaling device circulation drilling fluid in the well

   The application of this device allows you to control the absorption of drilling fluid in the borehole regardless of whether the fall of the liquid level due to changes in the resistance of fluid motion while reducing its velocity in the annulus wells at the installation switch.


   To determine the design parameters of signaling necessary to calculate the force exerted by the fluid on the valve – a dynamic pressure sensor. Since the theoretical solution of this problem is difficult, it was numerically simulated by finite element method.
   In modeling [2] determined the forces acting on the valve plate signaling device that allows you to choose a return spring valve and determine its sensitivity to changes in fluid flow.
   Calculations were performed for two structures with different modes of signaling rinse well, and taking into account the rotation of the drill string without it. In this case, the simulation for different sizes of valves – sensor speed pressure. The pressure drop across the valve is calculated by numerical simulation using finite elements.
   As an example, modeling that was conducted for the fluid flow rate 20-120 l / min for 93 mm diameter hole, covered with casing diameter of 89 mm with an inner diameter of 79 mm. Model on which the calculations were shown in Fig. 4. Simulation results were shown in Fig. 5


Fig. 4 – Computational grid model


Fig. 5 – Simulation results: a) rub-pressure; b) fluid flow rate.

   The simulation, we determined the force acting on the valve. For example, one of valve dependence of the force acting on the valve from the fluid flow can be approximated by the following equation: y = 0.010x2 +0.033 x-0.6. A plot is shown in Fig. 6.


Fig. 6 – Graph of the force acting on the valve on the supply of washing fluid

   Thus, for any value of the fluid from 20 to 120 l / min, using this relationship, we can determine the necessary effort, which should provide spring signaling the need for designing devices and developing the technology of its application.
   Taking into account the settlement was created a real signaling device design fluid circulation in the hole, 3-D model is made in the CAD package Compass 3D »and is shown in Fig. 7. In this model, developed design documentation for the switch.


Fig. 7 – A real 3-D model of signaling device circulating drilling fluid in the well

Conclusions and future research


   At this stage of the work was carried out an analytical review of drilling fluid absorption sensors based on which have been identified shortcomings in existing devices.
   Proposed a refined principle of signaling and structural scheme designed to implement it.
   For signaling circulation drilling fluid was simulated in the package «ANSYS» to determine the forces acting on the valve at his job. Calculations were performed for the well O93 mm with and without rotation of the drill string, with normal and elevated feeds drilling fluid and well O151 mm without rotation of the drill string. Based on these calculations, it was concluded that the rotation of the drill string does not affect the pressure loss in the switch. The results of the simulation allowed to design a switch for various drilling conditions.
   Have also been proposed rational relationship of design parameters that are included in the basis of recommendations from the application of the developed sensors.
   On the constructive scheme of the design signaling device circulation drilling fluid for use in wells. The design of signaling device patent of Ukraine for useful model number 50771 from 25.06.2010.
   Application of the developed design signaling provides the ability to more accurately and quickly identify the absorption of drilling fluid, which prevents accidents and saves resources and money.

References

  1. Патент України на корисну модель № 50771 МПК7 Е21В 25/00. Сигналізатор поглинання промивальної рідини в свердловині / Каракозов А. А., Парфенюк С. Н., Роль А. В., Сайгайдак И. Д., Назарян А. О. – опубл. 25.06.2010. – Бюл. №13. – 6 с., ил.
  2. Каракозов А.А., Парфенюк С.Н., Назарян А.О. Разработка сигнализатора поглощения промывочной жидкости при бурении геологоразведочных скважин / Наукові праці ДонНТУ. Серія "Гірничо-геологічна" Випуск 14(181), Донецьк, ДонНТУ – 2011, с. 252-256.