ARTIFICIAL LIFT Gas Lift

ARTIFICIAL LIFT

JOHN HARRY RAMREZ SNCHEZING. DE PETRLEOSUNIVERSIDAD SURCOLOMBIANA

RESERVOIR DRIVE MECHANISMS After the well has been completed, the hydrocarbons flow from the reservoir to the surface. This first period in the producing life of a reservoir is called primary recovery or primary production.

During this stage, natural energy in the reservoir often displaces the hydrocarbons from the pores of a formation and drives it toward the wells and up to the surface.

RESERVOIR DRIVE MECHANISMS In order of importance, the three natural forces that move the fluids in a reservoir are;

Water drive -when there is enough energy available from free water in the reservoir Gas drive -dissolved-gas drive (Some hydrocarbons in the oil become gaseous when the well releases pressure from the reservoir.)-gas-cap drive (Gas forms a cap on top of the oil. When there is an escape route for the oil in the reservoir, the pressure of the gas cap pushes the oil.) Gravity drainage- (Gravity causes oil to migrate upward, because water is heavier than oil.)

RESERVOIR DRIVE MECHANISMS

Gas-cap drive reservoir Water drive reservoirARTIFICIAL LIFT When pressures in the oil reservoir have fallen to the point where a well will not be produced by natural energy, some method of artificial lift must be used.

Artificial lift uses oil well pumps and high pressure gas to lift the oil from the reservoir.

The most common method of pumping oil in land-based wells is beam pumping. The beam pumping creates an up-and-down motion to a string of rods called sucker rods. The top of the sucker rod string hangs down inside the tubing. A sucker rod pump is located near the bottom of the well.ARTIFICIAL LIFT

WELL STIMULATION Sometimes, petroleum exists in a formation but it is unable to flow readily into the well, because the formation has very low permeability. If the formation is composed of rocks that dissolve by acids, such as limestone or dolomite, then a technique known as acidizing may be required. Acidizing a well consists of injecting acid (usually hydrochloric acid) into the well. In limestone or carbonate formations, the acid dissolves portions of the rock in the formation, opening up spaces to allow for the flow of petroleum. WELL STIMULATION When sandstone rock contain oil or gas in commercial quantities but the permeability is too low to permit good recovery, a process called fracturing may be used to increase permeability to a practical level. Fracturing consists of injecting a fluid down the well and into the formation under great pressure. Pumping continues until the formation literally cracks open. In addition to the fluid being injected, 'propping agents' are also used to prop open the newly widened fissures in the formation. Hydraulic fracturing involves the injection of water into the formation. Uses additional high pressure gas to supplement formation gas. Produced fluids are lifted by reducing fluid density in wellbores to lighten the hydrostatic column, or backpressure, load on formations. Is the only lift method that fully utilizes formation gas energy. External gas, injected into special gas-lift valves at specific design depths, mixes with produced fluids and decreases the pressure gradient from the point of injection to surface.GAS LIFT

Generally the most economical artificial lift method if a cost-effective gas supply is available.Reservoir pressure, suplemented by gas injected into tubing valves at specific depths to lighten the fluid column.In gas lift systems, downhole equipment and surface facilities are closely related. Because well parameters and conditions like reservoir pressure are dynamic, producing operations change over time.GAS LIFT

The productivity changes with time and specific problems like water or sand influx.Well factors include tubing and casing size as well as depth and completion configuration, type of gas-lift valves, wellbore hydraulics and fluid flow regimes.CHANGE IN THE PERFORMANCE

GAS LIFT NETWORKS AND FACILITIES

Gas-lift infrastructure includes compressors, separators, manifolds, field flow lines and export pipelines, which are closely related to subsurface equipment operation and performance. Changes in facility or reservoir performance influence both systems.GAS LIFT NETWORKS AND FACILITIES

Luence both systems14Electric submersible systems use multiple centrifugal pumps stages mounted in series within a housing, mated closely to a submersible electric motor on the end of tubing and connected to surface controls and electric power by an armor protected cable.Design and installation of ESP combine hydraulic, mechanical and electrical components in a complex subsurface environment. ELECTRIC SUBMERSIBLE SYSTEMS ESP

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High GOR fluids can be handled, but large gas volumes can lock up and destroy pumps.Corrosive fluids are handled by using special materials coatings.If the reservoir allows sand and abrasive particles to be pumped without adverse effects.Operating submersible pumps at temperatures above 350F (177C) requires special high temperatures motors and cables.

OPERACIONAL CONDITIONS

Historically, ESP were used in high water, low oil producers that perform like water wells.Wells deeper than 12000 ft can be produced efficiently with ESP.Depth and high GOR restrict capacity and efficiency.

Can lift high volumes of fluids. It manages high courts of water. It can operate to speeds of pumping variable. The surface team requires little space. Applicable OFF SHORE. The investment is low in shallow wells and with high rates of production. It can be used to inject fluids to the formation.

ADVANTAGESIt required to control the team in each well. Susceptible to the production of water, gas and sand. The electric cable is sensitive to the temperature and handling. It is highly expensive. it needs electric current. Their design is complex.DISADVANTAGES

CABLE DEPLOYMENT TECHNIQUESCABLE DEPLOYED AND COILED TUBING (TUBERIA FLEXIBLE)

VIDEO ESP

PCP are based on rotary fluid displacement. This spiral system consists of a rotor turning eccentrically inside a stationary stator. (See fig.) the rotor is a small diameter screw with deep round threads and extremely long pitch-distance between threads peaks.The stator has one more threads and longer pitch than the rotor, which forms cavities that progress in a rotating motion to create almost pulsation-free linear flow.

PROGGRESING CAVITY PUMPPCP

EL ROTOR ES UNA TORNILLO DE DIAMETRO PEQUEO CON ONDULACIONES PROFUNDAS ALREDEDOR Y DE DISTANCIAS SUMAMENTE LARGAS ENTRE LOS PICOS...Progressing cavity pumps produce up 1700 BPD and are used to depths of about 4000 ft (1200m). Elastomeric components operating temperatures to between 212 and 302F (100-150C) may not be compatible with some chemicals or H2S.

PCP SYSTEM

VIDEO PCP

MUCHAS GRACIAS

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