API RP 14B:2005 pdf download

API RP 14B:2005 pdf download.Design, Installation,Repair and
Operation of Subsurface Safety Valve Systems.
5.2 System requirements
5.2.1 General
The user/purchaser, when developing the system configuration, shall consider all the pertinent elements and their compatibility. These elements shall include the following: control system, control line, wellhead/tubing hanger passages and connectors, control line protectors, control fluid (for SCSSV); SSSV; flow couplings; locking and sealing devices (for wireline safety valves); safety-valve landing nipples; related tools and exposed fluids.
5.2.2 Installation
5.2.2.1 General
The user/purchaser shall assure that installation and installation testing of the SSSV system is performed and approved by qualified personnel using documented procedures and acceptance criteria in accordance with the manufacturer’s operating manual and operator’s system integration manual. System configuration and installation testing results shall become a part of the well records (see 5.4).
5.2.2.2 Control system
The surface-control system shall include the elements necessary to sense abnormal conditions that may contribute to uncontrolled well flow and shall transmit the necessary signal to the SCSSV for closure.
All elements of the integrated system shall be analysed for potential hazards that may render the system vulnerable to failure or may preclude safe use. For example, automatic resets shall not be incorporated in the control system since this feature may cause the SCSSV to reopen when it should remain closed. Systems shall be designed and operated to address the potential hazards to safe use.
It is desirable to integrate the SCSSV surface-control system into the surface safety system to avoid duplication. Features shall be designed in the integrated system whereby routine production upsets do not result in closure of the SCSSV(s).
If hydraulic or pneumatic control systems are utilized, the test pressure of those systems shall be equal to or greater than the highest operating pressure of that system when installed. System components shall be verified capable of meeting all anticipated environmental conditions, including temperature.
For multiple-well installations, the control-system manifolding shall include provisions for individual well and SSSV isolation.
ESD controls should be installed in strategic locations in accordance with applicable regulations and sound engineering judgement. To avoid closure of the SCSSV under full well-flow conditions, a delay shall be incorporated between closure of the tree valves controlled by the ESD and the downhole SCSSV. The opening sequence should be reversed on returning production facilities to normal operations. This delay mechanism shall be carefully analysed and documented to verify that it does not create additional hazards that render the system vulnerable to failure.
For additional information, see ISO 13628-6.
5.2.2.3 Control line
Prior to installation, the control line shall be verified as filled with the specified control fluid of the specified cleanliness. During installation, care shall be taken to ensure that, when fully installed, the control line has no detrimental physical damage that can cause fluid flow restriction, stress risers or corrosion initiation sites. See 5.3.1.7 for control-line selection criteria.
5.2.2.4 Wellhead/tubing hanger passages and connectors
Passages/connectors shall have the following characteristics/considerations:
a) the verified pressure rating shall be equal to or greater than the highest anticipated control-system operating pressure;
b) specific consideration shall be given to minimum passages being equal to or greater than the control line;
c) materials shall be compatible with the production environment and other fluids that may come in contact;
d) specific consideration shall be given to seal material applications for working pressures equal to or greater than 68,9 MPa (10000 psi);
e) the design and location of the wellhead outlet for the control line may include a valve for closure and isolation of the individual well from the control system. This valve shall be maintained in the open position during normal operations and it shall be readily identified when closed, since its closure will render the SCSSV inoperative.
5.2.2.5 Control-line protectors
Control-line protectors should be used to protect the control line from possible damage (abrasion, flattening, etc.) that could occur during running/pulling operations after connecting the control line. When used, at least one protector for each tubing joint is recommended. The cross-coupling types are recommended to prevent the protector from moving on the tubing joint. Protectors shall have dimensions compatible with the tubing size and connection, with the control-line size and type, and with the casing drift.
5.2.2.6 Control fluid
The requirements of 5.3.1.6 on control fluid selection apply.
5.2.2.7 SSSV
SSSVs shall be selected that have been verified as being compatible with the dimensions and configurations of: tubing and auxiliary conduit connections; tubing and casing drift diameters; related permanent well equipment and well-servicing tools; control or other fluids in contact with the equipment.
Well effluents and producing characteristics are principal factors in selection and design.
Scale, paraffin and hydrate deposition affect closure performance and should be carefully considered in determining the setting depth, especially for SSCSVs.
5.2.2.8 Flow couplings
Flow entrance effects can have an affect on SSSV performance. To reduce the resultant effects of turbulence during production, flow couplings should be considered an integral part of the tubing string, both upstream and downstream of the SSSV. Flow couplings should be compatible with the ID of the SSSV for an ample length prior to the SSSV entrance and at the exit. Typical industry practice has been to provide a minimum of 0,9 m (3 ft) in length provided it exceeds 8 to 10 times the ID of the tubing. In the case of TR-SCSSV installations, flow coupling length should take into account future insert valve installations.