Prepacked Screen – Ready‑to‑Run Sand Control Solution for Demanding Wells

Product Description

Prepacked screen (also known as a pre‑packed gravel screen or dual‑wall prepack screen) is a factory‑assembled sand control device that combines a perforated base pipe, an inner retention screen, a precisely graded gravel pack, and an outer wedge‑wire screen jacket – all in one complete unit. This "pipe + screen + gravel + screen" sandwich construction eliminates the need for costly and time‑consuming on‑site gravel packing operations. By delivering a uniform gravel layer that is pre‑compacted and securely held between two screen layers, a prepacked screen ensures consistent filtration performance from the moment of installation.

The base pipe (perforated with precision‑drilled holes) provides the primary structural backbone, while the inner screen retains the gravel fill and prevents it from entering the wellbore. The outer screen jacket – typically a high‑performance wedge wire screen – acts as the primary formation‑retention barrier, allowing formation fluids to pass while blocking sand and fines. The intermediate gravel layer serves as an additional filtration medium, distributing flow evenly and reducing fluid velocity near the screen interface to minimise erosion and plugging.

OASIS prepacked screens are manufactured using premium materials – base pipes in J55, K55, N80, L80, P110, SS304, 304L, or 316L – and outer screen jackets in SS304, 304L, or 316L to match any downhole environment. Whether you are completing a deep water well, an oil producer, a gas well, a geothermal borehole, or a vertical well, a prepacked screen delivers superior sand control, extended service life, and lower operational risk.

Specifications

Key Features & Advantages

• Factory‑prepared reliability – The gravel layer is uniformly packed and pre‑compacted under controlled conditions, eliminating the uncertainties of field gravel packing such as voids, bridging, or incomplete placement.

• Superior sand control – The triple‑barrier design (outer wedge wire + gravel pack + inner screen) provides multiple stages of filtration, effectively retaining fine sands while allowing high fluid throughput.

• Erosion resistance – The gravel layer acts as a flow diffuser, reducing fluid velocity and turbulence at the screen face, which significantly extends screen life in high‑production wells.

• Wide material compatibility – Base pipe grades from carbon steel (J55–P110) to stainless steels (304/304L/316L) allow you to match strength requirements and corrosion resistance to your specific well fluids.

• Flexible dimensions – With base pipe ODs from 4½" to 9⅝", perforation sizes from 9–19 mm, and thread options including BTC, STC, and LTC, we configure each prepacked screen to your wellbore geometry.

• Ready to run – Delivered as a single, pre‑assembled unit, prepacked screens reduce rig time, lower installation costs, and minimise HSE exposure associated with bulk gravel handling on site.

FAQ

Q1: How does a prepacked screen differ from a standard wire‑wrapped screen?
A standard wedge wire screen has only one filtration layer (the outer jacket). A prepacked screen adds a pre‑placed gravel layer between an inner and outer screen. This provides an additional filtration stage, reduces fluid impact velocity on the outer screen, and eliminates the need for separate gravel‑packing operations – making it ideal for unconsolidated formations where sand production is severe.

Q2: What gravel size is used in the prepack layer?
The gravel is sized according to your formation’s grain‑size distribution (typically 40/60, 20/40, or 12/20 mesh). We recommend a gravel size that is 5–6 times the average formation sand grain size. Our engineering team analyses your sieve data and selects the optimal gravel grade to ensure maximum retention and permeability.

Q3: Can I use a prepacked screen in a geothermal well with high temperatures?
Absolutely. For high‑temperature geothermal applications, we recommend base pipe and outer screen jacket in 316L stainless steel due to its excellent resistance to chloride stress corrosion cracking and high‑temperature oxidation. Our prepacked screens are successfully operating in wells with temperatures up to 300°C.

Q4: What threads are available, and can you match third‑party connections?
We offer standard connections: BTC (Buttress), STC (Short Thread & Coupling), and LTC (Long Thread & Coupling). We can also manufacture custom crossover subs or special threads to match your existing casing string or packer assemblies.

Q5: What is the maximum length per section, and how are joints connected?
Sections up to 12 metres are available in a single joint. Multiple prepacked screen sections can be connected in the field using threaded couplings or by welding between base pipes (with care taken to protect the screen jacket). We also supply blank pipe spacers and centralisers to complete your string.

Packing & Shipping

• Surface protection – The outer wedge‑wire jacket is wrapped with woven bags or bubble bags  and wrapped with wood strips to prevent mechanical damage during handling.

• End protectors – Both ends of the base pipe are fitted with heavy‑duty plastic thread protectors (for threaded connections) to safeguard the threads.

• Crating – Each prepacked screen is securely fastened inside custom‑designed wooden cradles or steel‑framed crates, with internal bracing to prevent movement and vibration during transit.

• Labelling – Every crate displays the purchase order number, specifications (OD, grade, length), batch code.

• Documentation – We provide full shipping documents, including commercial invoice, packing list, bill of lading, material test certificates, and dimensional inspection reports.

• Shipping mode – Export‑packed containers (20 ft / 40 ft) or break‑bulk for oversized orders. Lead time: 20–35 working days depending on quantity and material availability.

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Project Case Study – Custom Order in 316L

To illustrate our flexible manufacturing capability, we recently completed the following prepacked screen project:

This order demonstrates our ability to supply non‑standard lengths and fully stainless steel assemblies to meet challenging downhole conditions. We handle everything from material sourcing and perforating to gravel packing and welding of the outer jacket – delivering a complete, ready‑to‑run prepacked screen string.

Project Applications

OASIS prepacked screens are trusted in a wide variety of well types across the globe:

• Deep Water Wells – Municipal and agricultural water supply, where fine sand exclusion is critical for pump longevity.

• Oil Wells – Standalone sand control in unconsolidated sandstone reservoirs, reducing workover frequency.

• Gas Wells – Preventing formation fines from entering surface separation equipment.

• Geothermal Wells – Withstanding aggressive brines and high temperatures (using 316L / duplex materials).

• Vertical Wells – Easy deployment in straight boreholes with standard casing and packer assemblies.

• Highly Deviated or Horizontal Wells – The pre‑packed gravel layer ensures uniform filtration even when the screen is not perfectly centred.

OASIS provide free formation grain‑size analysis and slot/gravel sizing recommendations – simply forward your cuttings or sieve data, and our engineers will propose the optimal prepack configuration.

Related Products

Enhance your completion package with these complementary items:

• Single‑Layer Wedge Wire Screens – Standard outer jackets without the gravel fill (our base offering).

• Perforated Base Pipes – Casing with precision‑drilled holes (9–19 mm) in all grades, available as blank carriers.

• Centralisers (Bow‑Spring / Rigid) – Keep the prepacked screen string centred in the open hole or cased section.

• Thread Adapters / Crossovers – Convert between BTC, STC, LTC, and proprietary connections.

• Pup Joints & Subs – For precise length adjustment at the surface or between packers.

• Completion Accessories – Packer seals, landing nipples, and polished bore receptacles (PBR) to complete your downhole assembly.

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Ready to specify your prepacked screen? Contact our technical team today with your well parameters – we will deliver a full datasheet, engineering drawing, and firm quotation within 48 hours. Your sand control success starts with a prepacked screen built to your exact geology.