1. Size of the production test crew
A minimum of rig personnel should be on board during well-testing operations. Well test personnel will complement the rig personnel some time prior to the actual test operations and although it is desirable to keep the number of the latter group to a minimum, care should be taken that no person in either group will be committed to work excess hours. Mistakes resulting in damage and/or injury have sometimes been caused by fatigue of personnel. One of the measures to be taken to prevent accidents, therefore, is to avoid excessively long working hours. Operating companies should make sure that their supervisory staff in charge of operations, keep track of hours worked by all personnel, including themselves and contractors.
1.For a short duration production test (one zone, 24 hours flow period), two production test supervisors and a wireline operator are considered sufficient. When more zones have to be tested and the duration of the flowing periods may be several days or weeks it is advisable to have on board, one senior production tester, 2 production testers, 2 assistant testers, 1 wireline operator and a helper.
2.For operations involving the use of a subsurface test tree, two additional operators are required. These operators will be on the drill floor on a 12 hours on/off basis during the time that the SSTT is in the hole.
3.For downhole pressure and temperature measurement with surface read out, specialists are required. For long duration testing, it is advisable to have 2 specialists on site. When the production testing contractor also provides the reel unit with the electric cable, the regular wireline operator should be capable of running these tools alternatively, for BHP/BHT with surface read out, operations can be conducted by the logging contractor.
The fees for contract personnel are high, and operating companies must therefore insist on quality and should check the experience and curriculum vitae of service personnel. Some service companies may recommend that their chief operator carries out the actual wireline operations which would result in decreased charges. However, cost savings in this direction are misplaced. Experience has shown that the two functions are difficult to combine.
2 Company supervision
Throughout the production test there should be an experienced production operations engineer and a petroleum engineer on site who are familiar with both the practical production testing techniques as well as the theory.
3 Responsibilities/duties during testing operations
3.1 The Contractor Drilling Supervisor (CDS)
The Contractor Drilling Supervisor or Contractor Drilling Superintendent is responsible for the rig safety at all times and is the central point of authority. He has overall responsibility for the well and rig safety during all operations including production test and the suspension/abandonment operations.
3.2 The Company Drilling Supervisor
The Drilling Supervisor co-ordinates and monitors the operations and should keep himself fully informed of the progress of the test at all times. He must be advised by the Petroleum Engineer (PE) before the well is perforated and by the Production Operations Engineer before the well is opened up, and at any time that a potentially hazardous situation may occur. He in turn will inform the PE of any activity or occurrence which could effect production operations.
3.3 The Production Operations Engineer (POE)
The Production Operations Engineer supervises the operations of running the tubing, wireline work, opening up, beaning up, blowing off and testing of the well. He is responsible for the safety precautions on the surface production facilities from wellhead to flare. He ensures that an accurate record is kept of all information requested in the testing programme.
3.4 The Petroleum Engineer (PE)
The Petroleum Engineer is responsible for the test meeting the requirements of the test programme. He keeps a tally of all equipment run in the hole. He is responsible for logging, packer setting, perforating, stimulating P.V.T. sampling and in general for all the information generated by the test.
3.5 The Production Test Contractor
The Production Test Contractor has the responsibility to check all his equipment before the test and perform the necessary safety checks. During the test, the production test operators operate the choke-manifold, heater, separator, burners and transfer pump while taking the necessary measurements. The subsurface operators have to be on the drill floor near the controls of the SSTT on a 12 hours on/off basis. The production test operators should only follow the instructions of the Company Production Operations Engineer.
3.6 The Barge Engineer
The Barge Engineer remains in constant communication with the person in charge of the rig. He is responsible for the supply of air to the burners and for the supply of water to the water sprinkling system. When the cooling system is not sufficient he will rig up firewater hoses and flush the equipment which gets too hot. When steam is used as a heat exchange medium, he ensures adequate and continuous supply.
3.7 The Driller
The Driller and two floormen will be available on the derrick floor. The Contractor Drilling Supervisor may give the Driller specific instructions in connection with well/wellhead safety.
3.8 The Radio Operator
Before the radio transmitters are switched off for perforating operations, the Radio Operator must inform the standby boat and the base. He should remain in the radio room. Only one person should be empowered to order him to switch the equipment on and off; this is usually the Company Drilling Supervisor.
3.9 Miscellaneous
The assistant driller, derrick man or one floorman must be in the pump room, and have killing fluid and equipment ready for killing/circulating of the well.
The kill-pump operator must be available at all times, to pressure test and kill the well, when required.
4 Communication and reporting
The Production Test Contractor who reports directly to the Production Operations Engineer. Only the POE gives instructions to the Production Test Contractor(s).
The logging contractor, the mud engineer and the mud logging engineer who report directly to the Petroleum Engineer. Only the PE gives instructions to these contractors.
The POE and the PE make a joint progress report at the end of the day which is handed to the SDS unless otherwise agreed. For instance during running in the tubing it will be impractical to give all instructions via the SDS.
Although during the course of a production test it may seem impractical and time consuming to follow the reporting channels, it is of importance that everybody strictly adheres to it.
It is therefore advisable to have a meeting (normally the "Safety meeting") with everybody concerned (including radio operator, barge master, chief engineer, chief electrician etc.) where this subject is explained and discussed, before the test.
Although there is a strong tendency nowadays to contract out all services required on a well test, it is strongly recommended that overall control still be retained by having Drilling Supervisors and Petroleum Engineers.