Screens serve to protect pumps and pipelines from formation sand by blocking it off. To ensure their optimal performance, screens must be put through rigorous performance testing resembling reservoir or wellbore conditions.
This includes determining the pressure drop that limits a screen’s capacity to retain sand, as well as its resistance to erosion (Procyk et al. 2017).
Well Screens
Well screens serve an essential purpose: controlling sand formation in water wells. Inserted downhole during drilling, completion and well development stages to clean openings or widen passageways within water-bearing sand and gravel packs, well screens must be extremely damage resistant while still performing their primary function effectively against high compaction loads and must feature wide slot openings that avoid plugging up.
Stainless steel well screens provide the ideal solution for these demands, thanks to their exceptional corrosion resistance, high strength, and wide variety of sizes and types available. Their chromium content forms an invisible passive shield against further surface corrosion as well as keeping corrosive elements out of its internal structures. Furthermore, this metal boasts excellent electrical conductivity properties.
One type of well screen, commonly referred to as a bridge slot screen, features one orifice longitudinally aligned with two supports and made out of flat perforated metal sheets or plates fabricated on a press, then cut and welded into 5-foot sections for field installation.
Milled slot casing is another common choice of well screen, consisting of vertically slotted metal casing with slots cut by torchlight to facilitate easier cleaning of the well. Though inexpensive, its vertical slots often invite plugging up of wells reducing sand control efficiency.
Expandable Screens
Sand screens are used to keep sand out of oil or gas wells. They may be part of cased hole or open hole completions with gravel packs, or used standalone as stand-in screens. Sand screens may also be useful in mud logging applications to locate pockets of oil or gas reserves.
Expandable Sand Screen (ESS), an innovative new technology for controlling sand, has the potential to achieve lower skin irritation and higher productivity than internal gravel packs, openhole gravel packs, or stand-alone screens. However, in order to select this technology effectively and reliably. A thorough understanding of ESS characteristics must be obtained in order to formulate appropriate selection criteria for this solution.
Given the intricate relationships among functional layers, materials selection for ESS must take weldability into account in order to ensure its success. Furthermore, dissimilar material requirements between connections and base pipes necessitate that weldability be assessed in addition to considering weld integrity.
Ideally, the material chosen for sand screen applications must have good mechanical properties that allow it to withstand shear stresses while maintaining good mechanical properties and resist fracture and impact damage, while possessing high corrosion resistance – these attributes are especially essential when operating in abrasive formations. In addition, compatibility with reservoir chemistry and permeability is of vital importance; in particular phenol formaldehyde resins provide chemical stability as well as excellent abrasion resistance properties which will help prevent surface clogging while lengthening its lifespan over time.
Standalone Screens
Standalone screens have long been one of the primary methods used in oil and gas wells for controlling sand production. While they offer great control, their effectiveness may depend upon several factors including erosion, screen size, permeability and geology – as well as quality of sand used, installation procedures or natural packing behind it.
The most frequently used standalone screen type is the premium slotted liner screen made from stainless steel or Inconel, used for sand control in open hole horizontal wells and proven more effective than other stand-alone screens. Unfortunately, they may also be susceptible to producing and plugging due to frequent washing, circulation and acidization during well completion operations.
As soon as sand is produced from a well, it can enter the annulus and cause production issues, damage equipment and incur costly workovers. To combat these problems, a sand control system that effectively separates sand from fluid flow must be employed. Many different screen designs have been tested for retention and erosion control purposes – premium sand screens were found to have the highest retention capacity, followed by metal mesh and wire-wrapped screens, with other factors like screen design, particle size distribution and micron rating also having an effect.
Mechanical Screens
Mechanical screens are devices used to separate materials by creating segregation. Mechanical screens come in the form of either coarse or fine screens; with coarse screens having an opening between 75mm and 150mm for use in clearing away coarse solids that might otherwise clog or damage other equipment; fine screens having opening ranges 5 mm are fitted around drums to separate materials as they pass through, with retained solids collected through backwashing.
Assuring maximum efficiency in oil and gas production requires selecting an efficient screening device. Gaining knowledge about different types of screens’ functions will enable operators to select one best suited to their project by considering key material characteristics, machine characteristics and desired product specifications when making this selection.
Mechanical screen technology offers numerous benefits. These include high strength and durability, increased gravel pack capacity, reduced power usage for crushers and conveyors, as well as extended screen life. Some types of screens also provide superior erosion resistance and sand control capabilities.
PalmSHIELD produces a variety of mechanical equipment screens. Louvered screens are an excellent way to conceal electrical units, breakers, compressors, trash equipment and other devices from public view while providing adequate ventilation without compromising privacy.