API RP 92U:2008(2013) pdf download

API RP 92U:2008(2013) pdf download.Underbalanced Drilling Operations.
4.4.2.9 A detailed HAZOP review shall be conducted for all critical sour well UBD projects. Each weilsite operation may be unique (location, prevalent winds, facilities hookup, local impact, etc.) and consequential result of failure may be different.
4.4.3 Quantitative and/or Qualitative Risk Assessment
4.4.3.1 The risk of a blowout is one of the major contributors to the overall risk associated with conventional drilling operations. Moves towards requirement for rig safety cases in many jurisdictions have placed increasing focus on risk and have resulted in greater attention to the validity of the statistical failure data used in quantitative risk analysis (QRA). In general, safety case documentation includes but is not limited to:
— an assessment of risk to people, assets and the environment, and
— identification of preventative and mitigating measures to ensure that risks are as low as is reasonably practicable
(ALARP).
4.4.3.2 The determination of the risk level is based on a risk assessment matrix as shown in Figure 2. The matrix and the following explanation are included here for information only. Risks are deemed unacceptable in the boxes marked Medium or High Risk. If risks are identified within this sector of the matrix, then additional controls are required in order to shift the risk out of the sector. It is acceptable that such analysis is performed in a qualitative fashion based on reasoned judgment and expert opinion, other than where regulations may have specific requirements.
4.5 Project Approval
4.5.1 Project Plan
4.5.1.1 The overall project plan to undertake the UBD of a well should be signed by a qualified and coporatelyauthorized technical representative. That representative, by his/her signature, will be confirming that all the requirements of this document have been addressed in the plan and that the elements of the plan will be applied during the execution of the plan. The signature will also confirm that appropriate input from qualified technical experts has been obtained when required and that the qualifications of the technical experts are valid.
4.5.1.2 If the planned underbalanced well meets the definition of critical sour, the overall project plan shall be signed by a qualified and corporately authorized technical representative.
4.5.1.3 It is the operators responsibility to ensure that the required technical judgment has been used to develop the project plan and will be used during the execution of the project.
4.5.1.4 Competency assessment and training should be part of the plan.
4.5.2 Qualified Technical Expert
This document allows flexibility in practices provided a qualified technical expert relative to the practice/technology has approved the options in question. It is the operator’s responsibility to ensure that the expert is qualified as competent by normal industry standards.
4.6 Emergency Response Plan (ERP)
4.6.1 A site-specific ERP for the UBD operation should be developed which addresses operating company policy and appropriate regulatory requirements.
4.6.2 The ERP should address both drilling and production operations. During conventional drilling operations, the ERP (in most jurisdictions where one is required by regulations) is implemented if there is a serious well control incident (total drilling fluid losses encountered or unplanned flow of formation fluids into the welibore). During an uriderbalanced operation, there is continuous, planned, and controlled flow of formation fluids into the weilbore and the normal ERP implementation criterion does not apply.
4.6.3 The circumstances or events, which trigger implementation of the ERP plan shall be stated in the ERR
4.6.4 For a critical sour IJBD operation, a ERP for the EPZ shall be developed which addresses the appropriate regulatory requirements. In the absence of such regulations, the criteria as outlined in AEUB ID 90-1 should be referenced and followed as an industry best practice.
4.7 Underbalanced Drilling Operations Plan
A UBD operations plan should be developed and should address the following (see Figure 3).
a) Appropriate regulatory requirements.
b) Casing design.
C) Casing wear—acceptance criteria.
d) Completion design.
e) Directional plan.
f) Drill pipe safety valve operating practices. Especially, important consideration for drilling underbalanced with
casing.
9) Geological hazards.
h) LWD operating practices.
i) Drilling fluids program.
j) Tripping operating practices.
k) LJBD BHA, drill pipe, NRVs, etc.
I) Well control/kill operating practices.
m) UBD surface equipment operating practices (vis-vis an open, partially open, or closed circulating system).