The designer must ensure that there is critical flow through the choke in order to eliminate the effects of downstream pressure variations on the formation. This is achieved when the FTHP is approximately 1.7 times the downstream flowline pressure. There are additional factors to be considered in choke selection. 1 Actuated chokes By its very … Wellhead Chokes
In the design process for all wells, consideration should be given to the repressurisation of the Christmas tree after it has been closed in. Several approaches may be taken depending on the circumstances and the design of the well. In the case of the well being shut in and depressurised with full pressure below the … Equalisation of christmas trees
The wellhead is simply a crossover between the various casings and the Christmas tree or -temporarily – the BOP. Unitized wellheads The evolution from spool type wellheads to compact, or uniheads has occurred over a number of years. This evolution has generated a wellhead which is technically superior, offers enhanced safety and rig time saving, … Wellhead selection guidelines summary
This article describe the completion packer selection, specifications, classification, setting mechanism, etc. Packer selection/specification … Completion Packers
Tubing movement and stress behaviour are a function of the well temperatures and pressures: The changes in temperature will cause the tubing to expand and contract. For example, 10,000 ft of tubing suspended in a well will shorten by 16.6 inches with a temperature drop of 20°F. Pressures inside and outside the tubing above the … Tubing movement, forces and stresses
Sequence of Operations: 1. M/U flow head assembly and pressure test selectively to 150 bar as follows: 1) From bottom up against bottom master valve. 2) From bottom up against swap and fail safe valve. 3) From bottom up through open fail safe valve against low torque valves of kill and flow line. 4) From … TCP Perforating Programme
Proper preparation of tubing before running serves two purposes. Firstly to ensure that the pipe body and threads are adequately protected from possible damage when being moved to the drill floor. Secondly, that handling of the tubing on the drill floor is kept to a minimum. 1 Identification and measurement Electronic tagging will eliminate the … Preparation for running tubing
A packer is defined as a sub-surface tool used to provide a seal between the tubing and casing (or wall) of a well, thus preventing the vertical movement of fluids past this sealing point. Packers are sometimes referred to as production packers but this term is generally used with reference to a particular class. 1 … Completion Operations – Packer (introduction)
Material selection is determined by the abrasion and corrosion properties of the fluid, the pressures and the mechanical and hydraulic loadings on the completion string under operating conditions, e.g. stimulation, injection and production conditions. Tubing stress calculations will allow specification of threaded coupling type, and material as well as identifying the need for a dynamic … Completion Tubing – Material Selection
Whatever type of packer is installed, the manufacturer’s instruction for setting and the completion programme on setting depth and running must be followed if satisfactory results are to be obtained. There are too many variations in packer design and setting to go into detail, but some points to remember when installing packers are: do not … Completion operations – Setting packers