Wellhead equipment for drilling

Wellhead - a set of equipment for piping casing, sealing the well head if necessary during drilling, workover, sealing the mouth and regulate wells during its espluatatsii. Conditionally all wellhead equipment is divided into equipment used in drilling the well and its espluatatsii.

The composition of wellhead equipment, participate in tying the mouth while drilling include casing head and blowout preventer, which consists of the following units: spiders, BOP, coils, detachable chute manifold, gidrouprovleniya preventer and valves, manually operated.

Casing head, through which tied with casing while drilling, is also the basis for setting Christmas tree, and she remains in the well for the entire period of operation.

The structure of the operating wellhead equipment also includes: christmas tree, Christmas tree manifold, valve replacement device under pressure lubricator used in studies of wells, a set of valves, subs, and other parts needed for assembly and binding wellhead.

Wellhead Equipment can be classified as the conventional components. Wellhead products that consist of base plates which are easily detachable from the casing head for reattaching and welding. Equipment like them provides extra load for supporting the higher case loads. Wellhead casing has a straight bore design that accepts casings of different hangers. The line pipe threaded outlets, studded or flanged outlets can be also provided. Bottom preps include a slip on weld and threaded connections.

Equipment like casing hangers combine pack off and slip bowl hangers. Wellhead is easy to install and is also fluted for allowing the cement returns. Wellhead Equipment can also be included as the casing spools that have a top bowl configuration. Equipment has locking pins. Wellhead secondary seals help in the installation of tubing heads and casing spools to provide pressure energized secondary seals. Wellhead tubing has a fully opened straight bore design with a dual completion head available and is compatible with a variety of tubing hangers

Installation methods of the lower section for wells in the reservoir area. Areas of application for each method.

 

Factors, that impact on deteriorated reservoir properties while drilling the reservoir.

 

Deterioration of reservoir properties of the PPP due to natural conditions (reservoir lithology and composition, physico-chemical properties of reservoir fluids, the actual thermodynamic conditions and the impact of drilling-technology, well operation and maintenance.

Formation damage, containing clay, is due to their sensitivity to water. The effect of swelling montmorillonite clay leads to deterioration of near-wellbore permeability. On the other hand, swelling of kaolinitic clay is due to clogging of the solid particles in the clay layer is usually present in the flocculated state because of the high salt content. During the drilling of the well water based ionic strength of the surrounding medium of clay is reduced by increasing the ionic membrane. The result is redispergatsiya clay and its migration into the micropores. Formed in this Microfiltration crust lead to plugging of the formation.

Another possible reason for the deterioration of reservoir properties because of capillary phenomena - emulsification of oil inside the pore, which can occur if the filtrate emulsion (oil in water) fluid contains significant amounts of emulsifier. Emulsification is due to the increase in the shear rate in the narrowed filtration channels, although the overall rate of flow is low. If this form a stable emulsion droplets her locked in the pores and reduce the effective permeability. However, the emulsifier is present in the filtrate only when the emulsion drilling fluid has a surplus. Therefore, we can avoid the emulsification in the bed, if you carefully select and support the structure of the emulsion solution