INDEX

Sand Control Methods
Application of Formation Sand Screen™ screens
Mechanical Strength
Formation Sand Screen™
Completing a Well
Remedial Operations
Quality Assurance

 

COMPANY PROFILE

   BK Sand Control is a German manufacturer of qualtity screens and has developed one of the world’s most modern screening-machines capable of manufacturing heavy duty Formation Sand Screens™ (FSS) with unique strength and flow characteristics, allowing application of these screens in long reach sections of highly deviated and horizontal wells.

 

SAND CONTROL METHODS

 
   For sandstone reservoirs the completion and production process becomes complicated if the reservoir has a tendency to produce sand. If not effectively controlled, the sand can cause plugging and erosion of production lines, formation damage due to sand migration, and erosion of downhole / surface production equipment.
   Completing a well in reservoirs with sanding problems is rather complex and several different methods are available for controlling sand production. Experience to date has shown that many screen systems are susceptible to plugging by fines and debris. There have also been reported cases of installation difficulties and failures especially in highly deviated and horizontal wells.
   Gravel packing is often used as a barrier between the formation and the screen. A careful study is required to determine the correct sizing of gravel to stop formation fines without forming a permanent flow restriction. Gravel packing is also limited with respect to the maximum length of the trajectory in horizontal wells that can be gravelled successfuly.
   The most economical method to complete a well is the use of a single screen in open hole with the formation sand packing around the screen. These stand alone screen installations require the screen to function as a downhole filter rather than a gravel retention device.

 

APPLICATION OF Formation Sand Screens™(FSS)

 
   BK Sand Control Formation Sand Screens™ are often applied as stand alone screens in highly deviated and horizontal wells. The construction offers many benefits with respect to strength, flexibility and productivity and proves to be an economical method for effective sand control.

 

 

MECHANICAL STRENGTH

   High strength of the screen structure is achieved by a special welding process allowing full fusion welds between the surface wire and the support structure. This modern manufacturing method no longer limits the screen design and allows for fabrication of a single and heavy duty screen.
   Compared to the conventional method for manufacturing a light screen structure (jacket), which in turn requires a base-pipe for strength, a Formation Sand Screen™ has a solid integral construction, which no longer requires the aid of a base pipe for its structural strength. Furthermore a new and patented method is used to weld the threaded connections to the screen structure, without weakening its original strength
Technical Data of Std. API Sizes:
    2.7/8" 3.1/2" 4.1/2" 5.1/2" 6.5/8" 7"
Std. API weight: p.p.f. 6.4 7.7 13.5 17 24 29
O.D. of screen inch 3.46 4.21 5.00 6.06 7.40 7.63
I.D. of Screen inch 2.48 3.17 3.88 4.88 5.94 6.2
Collapse pressure psi 2290 2000 2190 1920  2360 2480
Burst pressure psi 2970 2230 2690 2170  2270 2190 
Tensile strength lbf 83100 103400 130000 212500  244000 261800 
Column strength lbf 27 700 34500 43100 71000 81800 87500 
Allowable dogleg ° / 30 m 36.7 30.5 25.1 16.7 13.6 13.3
Torque strength Ft.lbs

Limited by connection strength
 

Flexible Completion Assembly

The screen structure is highly flexible and beats any comparison with similar sized screen designs. The short bending radius which can be reached with the BK Sand Control FSS has many advantages when completing a well to run through critical spots in the drilling trajectory.

Formation Sand Screens(TM) have already been run in horizontal sections of up to 4,800 ft. in length. 

 

 

High Flow Capacity

An important factor is the venturi-shape of the slot, contributing to the high inflow capacity of the screen structure. This venturi shaped flow entrance also prevents the screen from becoming plugged since the flow opening has a self-cleaning effect.

 

The flow capacity of Formation Sand Screen(TM) is virtually unrestricted in relation to even a high permeable formation. No debris can settle between the screen surface and support structure, thus preventing the screen from becoming plugged after a period of time.
 

 

Flow and Pressure Loss Graph

 

 

Formation Sand ScreenTM 

   Formation Sand Screen™ is the expression used to highlight the unique feature of the BK Screens to access the formation through the screen structure after installation. Many types of screen, whether being pipe based, pre-packed or with multiple mesh layers, seal-off the formation from the screen ID.
   Formation Sand Screens™, enable easy clean-up of the formation prior to bringing the well into production or after a number of years in service.
This ability to clean the formation through the screen structure by means of acidizing or CT jetting methods, even after years of service, may be considerd as a major advantage since it eliminates the need to re-work a completion after a productivity decline.

 

COMPLETING A WELL

   FSS Screens can be run and suspended in a similar to standard liners, without any special / additional equipment. Nominal screen sizes are compatible with regular API tubular- and connection dimensions.
  As a rule of thumb stand alone screens should be positioned as close as possible to the formation, allowing approximately 1,5” total radial clearance between the screen and the formation. Success of many screen completions depends largely on the completion strategy in terms of wellbore clean-up, drilling completion fluid displacement and handling of fines and filter cake debris.
   Hole preparation prior to the running of screens is of vital importance. Analysis of the well trajectory and a check trip shall ensure the proper hole conditions. Furthermore the screens are generally guided by solid body zinc alloy centralizers in deviated and horizontal sections, which considerably reduces the drag force.

 

REMEDIAL OPERATIONS

   More and more thru-tubing coiled tubing and wireline completions allow the use of screens to be hung off in the original completion string, by way of easy interventions. Coiled tubing completion techniques have revolutionized workovers, making them among the most cost effective and efficient methods available for well re-completions where sand production causes problems.

   The screens are designed to have maximum ID's to minimize pressure drop and have small OD's to enable to pass through nipple restrictions in existing completions. The high flow capacity of the BK Sand Control screen offers an economical method for reworking existing wells

 

QUALITY ASSURANCE
   The modern manufacturing facility of BK Sand Control guarantees the delivery of high quality screens according to many international manufacturing standards. The design, manufacturing and service of BK Sand Control is in line with ISO-9001 requirements and many research and testing is performed to maintain and improve the quality of the products. We are proud to show the benefits of BK Sand Control screens to any of our customers and look forward to benefit from our mutual experience.