2- Life Of Well

Life of Well / Main phase in completion

Well Types of wells At Production Phase: 1-Oil Wells  Naturally Flow Producing Wells  Lifted Producing Wells 2- Gas Wells 3- Water / Gas Injection Wells

Well Types of wells An Oil well is any boring through the earth surface that is designed to find and acquire liquid hydrocarbons; usually some natural gas is produced along with the oil A Gas well that is designed to produce mainly gas, sometimes may be this gas is associated with oil Water injection well or water flooding refers to the method in the oil industry where water is injected into the reservoir, usually to increase pressure and thereby stimulate production, can be found on and offshore

Life segment of Oil & Gas well Life segment of an oil or gas well • Planning • Drilling • Completion • Production • Abandonment

Life segment of Oil & Gas well Planning • Planning Objective: the objective of well planning is to formulate from many variable a program for drilling a well that has the following characteristics: safe , minimum cost and usable. Well type completion: the drilling engineer is required to plan a variety of well types, including : wildcats well, exploratory holes, step-outs well, in-fills and re-entries .

Formation pressure : the formation, or pore, pressure encountred by the well significantly affects the well plan. The pressure may be normal, abnormal (high) or subnormal

Life segment of Oil & Gas well Drilling The well is created by drilling a hole into the earth using a drilling rig that rotates a string with a bit attached. to drill we need:

1) 2) 3) 4) 5) 6)

A way to descend (DRILL PIPE) A way to rotate the pipe (KELLY or Top Drive) A place to hold the pipe (Derrick) A way to raise & lower the pipe (draw works) A cutting tool (BIT) A media to remove cutting (MUD)

Life segment of Oil & Gas well Drilling The Rigs come in a variety of configurations and designs for surface environments that range from Arctic to desert, ocean to midcontinent and just everything in between Types of Drilling Rigs:

1) Land or Onshore rigs 2) Offshore Rigs which classified to: a) Jack –Up Rigs b) Submersible Rigs c) Semi-submersible Rigs d) Platform Rigs e) Drill ships

Life segment of Oil & Gas well Drilling crew The Crew who are going to operate the rig consists of the following :

1) 2) 3) 4) 5) 6) 7) 8) 9)

Rig supervisor Tool pusher Driller Mechanics & electricians Derrick Man Crane Operator Floor Men Rough Necks Motor Man

Life segment of Oil & Gas well Drilling After a hole is drilled, sections of steel pipes (Casing) slightly smaller in diameters than the borehole are placed in the hole. Cement is placed between the outside of the casing and the borehole to provide structural integrity to a newly drilled well and isolate pressure zones from each other and from the surface Modern wells often have two to five sets of subsequently smallest hole sizes drilled inside one each other. Each is cemented with a casing.

Life segment of Oil & Gas well Drilling Mud is the drilling fluid pumped down the inside of the drill pipe and exists the drill bit. Drilling mud is a complex mixture of fluids, solids and chemicals that must be carefully tailored to provide the correct physical and chemical characteristics required to safely drill the well There a 2 type of mud:  Oil base mud  Water base mud

Life segment of Oil & Gas well Production The production stage is the most important segment of the well's life when the oil and gas are produced from the attached reservoir

At this stage the rig or the work over installations has moved off the wellbore and the top is fitted through the christmass tree to production network

Main phase in Completion Main phase in completion Well completion may involve different phases and the order of those phases can vary, the procedure below is only one among many possible solutions since certain phases can be carried out at other times or may prove unnecessary :

• • • • • • • • •

Checking and conditioning the borehole Remedial cementing Re-establishing pay zone – borehole communication Well testing Treating the pay zone Equipment installation Putting the well on stream and assessing performance Moving the rig Later operation : measurements, maintenance, workover and abandonment

Main phase in Completion Checking and conditioning the borehole This operation consist in checking the condition of the borehole . In an open hole this usually means simply running bit back in the hole to the bottom and circulating in order to get uniform mud For the cased hole the operations are more numerous : - A drill string equipped with a bit and a run in - the top of the cement in the casing is checked with the bit - The area where the packer is to be set is scrapped - Logs are run to check the cement bond quality - Depth checking logs are run : using gamma ray and casing collar locator CCL

Main phase in Completion Remedial cementing In case of the cement bond quality is inadequate, the casing is usually perforated and cement is injected under pressure opposite the area that were improperly cemented .

Re-establishing payzone borehole communication In a cased hole, the barrier consisting of the casing and the cement between the reservoir and the wellbore must be bypassed, doing a perfoartions are only the way to restoring this communication

Well testing All wells must be tested in order to ascertain the productivity/injectivity index and any possible damage

Main phase in Completion Treating the pay zone Well treatments mainly encompass sand control and well stimulation (acidizing , fracturing )

Equipment installation The basic conventional equipment (packer, downhole equipments, tubing, wellhead) may also be supplemented by specific safety or artificial lift equipement

Putting the well on stream Putting the well on stream include a clearing or unloading phase if treatment carried on the layer, or putting the well on production from the layer by eliminating the killing fluid

Main phase in Completion Moving the rig Rig can be moved once all of the operation have been concluded or as soon as the permanent equipment has been installed

Later operations Equipment requires maintenance to keep the well producing properly, it may also undergo workover for repairs or to modify production conditions