Wellhead Movement Analysis and Surface Casing Integrity in Pre-Salt Wells

As a general practice in the oil and gas industry, the well foundation, composed by the conductor and the surface casing, is designed with a strict tolerance regarding cement shortfall on the surface casing. However, in a pre-salt scenario, in order to reduce the costs of well construction, the surface casing shoe generally reaches the top of salt. In this case, it is quite hard to make the cement job reach the mudline due to problems like salt dissolution (generating high calipers) and presence of many geological faults in the post-salt zone (which can work as a lost circulation area). Besides that, an evaluation of the wellhead movement is necessary so that the structural restrictions of subsea equipment connected to the wellhead are not violated. This work had the goal of presenting a coupled structural model to analyze the foundation of a subsea well with a partially cemented surface casing, where the safety factors of surface casing are evaluated in the whole well life cycle along with the wellhead movement due to the loads related to each step of this cycle. A sensitivity analysis on the top of cement (measured from the casing shoe) is made, varying it from 300 m to 800 m. The results showed wellhead movement consistent with what is observed in the field, once no axial movement has been reported. Additionally, it was highlighted that the foundation design depends on the operations during the well construction and its future purpose, production or injection, because the thermal loads associated with operations have different impacts.

CALCULATION OF THROTTLEMENT PARAMETERS IN PARALLEL CHANNELS OF DRILLING PIPERS FOR DEEP HOLE

The article presents a method for calculating the characteristics of the throttling elements of the lubricating-cooling technical medium (COTS) Yu used in deforming piercing. A feature of the proposed technique is the method of supplying cutting fluids under pressure through the grooves made on the outer surface of the mandrel teeth, when the pressure of the working medium and its flow rate are divided into parallel flows, one of which provides pressure on the piercing when the hole is mandrelled with a normalized speed in its axial movement the second provides the calculated parameters of throttling between the surface of the grooves on the mandrel teeth and the machined surface, where they create "damping cushions", improving the mandrel process and reducing wear of the piercing [3]. The presented calculation of the characteristics (coolant pressure, flow rate, etc.) with the location of the conditional chambers formed by the grooves of the punching teeth and the processed surface confirms the possibility of using throttles to implement the conditions for using throttling elements during cutting-deforming piercing of deep holes in long tube blanks and increasing by this basis of its effectiveness.

Flexible multiplane structured illumination microscope with a four-camera detector

Fluorescence microscopy provides an unparalleled tool for imaging biological samples. However, producing high-quality volumetric images quickly and without excessive complexity remains a challenge. Here, we demonstrate a simple multi-camera structured illumination microscope (SIM) capable of simultaneously imaging multiple focal planes, allowing for the capture of 3D fluorescent images without any axial movement of the sample. This simple setup allows for the rapid acquisition of many different 3D imaging modes, including 3D time lapses, high-axial-resolution 3D images, and large 3D mosaics.

Determination of residual stresses during flaring of heat exchange tubes

The calculation of residual stresses in the attachment points of heat-exchange tubes in tube sheets during flaring is proposed, taking into account the peculiarities of axial movement of the spindle and local deformation of the tube under the influence of rollers. The calculation was based on the theory of continuity of a continuous medium and experimental data. Keywords: flaring, pipe, tube sheet, stress, deformation, torque. [email protected]

DETERMINING THE CHARACTERISTICS OF A MODIFIED AUGER

Screw conveying mechanisms with an active rotating casing and the location of the blades on the inner surface of the pipe are known, but are practically not used. They are not much more complicated than conventional augers in the manufacture, but they have a higher specific performance, and most importantly, they can not fundamentally pinch and crush grain. Despite the simplicity of the design, there are many different models describing the relationship of design parameters with output characteristics. Empirical coefficients play an important role in calculations. The task was to find out what is common and what is different in the mechanics of the process on the basis of consideration and clarification of the active forces. The scheme of forces has been significantly simplified due to the rational choice of the coordinate system. Positive answers were received to questions about performance, increased productivity, additional advantages, and determining the speed of axial movement of the material. some simulation experiments were Conducted to clarify the physics of movement when parameters were varied.

MODELING THE WORK OF THE HEAD OF A HYDROMECHANICAL EXPANDER FOR WELDED PIPES OF A LARGE DIAMETER

Finite element simulate of the operation of the expander head during the calibration of welded bulky pipes was carried out. The forces required to move the parts of the expander power drive are determined. It is shown that a change the length of the cylindrical surface of the wedge segments of the expander and the axial movement step size with constant radial extension of the segment changes the distribution of plastic deformation in the tube billet s.

Study of the Interaction of a Packing Device with a Coal Seam at Interval Hydraulic Fracturing

The technological scheme of the interval hydrodynamic influence on the coal seam is considered. The design of a double-sided packer is presented, the results of laboratory tests to determine the axial movement of the seals during the interval fracturing are shown. The numerical scheme based on the Finite Element Method has been developed for calculating the stress-strain state of a rock in the vicinity of a well, loaded by internal pressure through packer seals. The pressure acting on the contacts between the seals and the well is calculated, the stress distribution in the geomaterial is investigated.

Effect of impeller blade curvature on the hydrodynamics and power consumption in a stirred tank

The performance of curved bladed turbines (CBTs) for the agitation of Newtonian fluids in cylindrical tanks is investigated. The efficiency of CBT is compared with that of the standard Rushton turbine. Also, effects of the blade height of the new designed impeller are highlighted. The computational fluid dynamics (CFD) study is performed to observe the axial, radial and tangential components of velocities, flow patterns and power consumption. The obtained results revealed that the increase of blade curvature reduces the power consumption. Also, a slight decrease of power number is observed in the turbulent flow regime within unbaffled tanks. In a comparison between the cases studied, the best axial circulation of fluid is given by the impeller with flat blades. The increase of the height of curved blades has generated a stronger tangential flow and enhanced the axial movement of fluid particles, but with further penalty in power input.

Оptimization of design parameters the safety spring-ball clutch

A dependence is found that takes into account the current axial movement of the movable coupling half and the constancy of the maximum axial movement of the movable coupling half of the safety spring-ball coupling. It is shown that there is a limit distance at which the ball protrudes from the socket at the time of reducing the torque at the exit of the coupling halves from one another.