Oilfield equipment

Connecting thread to rods

INSERT PUMPS

The two-plunger insert pump with two-stage compression and with a bottom lock is designed for fluid production, containing up to 0.062 lb / ft3 of mechanical impurities and up to 25 % of free gas at the pump inlet.

On plungers upstroke a rarefaction is created in the area of the lower barrel, located over the standing valve. This allows the formation fluid entering this area with the standing valve opened. On the following downstroke the fluid being compressed flows from this area into the area, located between the plungers, the lower valve opened. Since the interplunger area is smaller by volume than the lower barrel area, the pressure of the gas-liquid mixture in it will be greater than a suction one. On the next upstroke the fluid between the plungers, being again compressed, is displaced into the tubing string with the upper valve opened.

The repeated compression of the fluid in the pump allows avoiding pump blocking when the gas content is high.

The drainer device provides fluid drain from the tubings directly when withdrawing (pulling out) the plunger before lifting the pump, without using a catcher or a breakable pin.

The automatic coupler allows lowering the pump with the drainer device cone preliminary mounted in the seat, thus providing reliable sealing of the drain unit.

The cavity between the sludge trap body and the external barrel surface serves as a collector for mechanical impurities, settling down when lowering sucker rods into a well and on pump shutdown. The protection bushing, fitted in the sludge trap cone prevents from the ingressing of contaminants into the pump barrel cavity. The pump design permits to minimize the amount of «adverse space» (the cavity between the standing and traveling valves with the lower plunger position), and also to equalize pressure inside and outside of the barrel and to allow relieving its tensile stress.

This design of the pump employs a short barrel and an oversized standing valve with a breakable pin. The pump is used when the mechanical impurities content is more than 0.062 lb/ft3.

Increased lifetime because of the constant contact of the barrel and the plunger makes it so that the mechanical impurities practically do not enter into the plunger-pair clearance. Nowadays the pumps are used in Tatar Republic, Bashkiria, Kazakhstan and Sakhalin. The working time of PKNM equipment is increased in 1.5–2 times if to compare it with the standard SSRP.

The SSRP construction is patented.

The pump design includes a relief valve that excludes standing valve’s blocking by gas that is released in the cavity under the traveling valve.

The pump is equipped with the standing valve that has a breakable pin.

SSRP FOR PRODUCING HIGH VISCOSITY OIL

The pump is meant for producing high viscosity
crude.

The pump of a special design includes a fixed barrel inside of which a barrel with a traveling
valve is moving. Inside of the movable barrel there is fitted a plunger with a standing valve rigidly linked with the fixed barrel. When fluid is delivered, there is created a cavity in the pump with a reduced pressure that allows the decreasing of forces moving the fixed barrel with the sucker rod string on its return stroke. This prevents the sucker rod string against «hanging-up» because of the excessive friction forces in pumping out high-viscosity oil.

VALVE WITH A BREAKABLE PIN

It is used for draining the fluid off the tubing string, when pulling up. The fluid drain takes place when a bar is dropped in the tubing string, cutting away the breakable pin and opening the drain hole. The advantage of this design is absolute reliability as opposed to the commonly used valve with a bayonet-type catcher, and this makes it possible to exclude cases of pulling out the tubings, filled up with formation fluid. For production of viscous oil there is used the standing valve with a larger flow area, also equipped with a breakable pin.

ADJUSTABLE DOWNHOLE FILTER

The filter is intended for protection of the sucker rod pump against ingress of contaminations contained in the pumped-out fluid. The filter consists of a body with orientating ribs and longitudinal slots, inside of the body there is a spring acting as a filter-element. Fineness of filtration (from 0.0078 to 0.0314 in) is provided by adjustment of between-coil clearance of the spring with the help of the adjusting screw with a rod.

AN AUTOMATIC COUPLER AND A SLUDGE TRAP

The automatic coupler is designed to connect the sucker rod string with the SSRP plunger directly in the

well. This allows lowering of the tubing pump barrel and plunger together and to avoid fouling of the barrel

with mechanical impurities (scale, mud etc.), that occurs when the barrel and the plunger are separately

run into the well. The sludge trap protects the pump from the side of the tubing space. The contaminants

(scale, mud etc.), settling down when lowering the rod string, are accumulated in the trap cavity and do not get into the pump.

The Gas-Sand Anchor is installed at the pump inlet of SSRP and serves for protection against free gas and mechanical impurities.

Gas-sand anchor dimensions, inch:

Longitude (without mechanical impurities collector) – 93.31 inches; OD – 4.134 inches; Weight – 125.9 pounds; Tubing diameters – 2 3/8; 2 7/8; 3 inches. The number of tubings installed as mechanical impurities collector – 2-3 pcs. Production rate – 314.5 bls/day.

Anchor setting depth under the dynamic head – up to 197 ft.

Fluid characteristics:

Watercut, % - up to 99;

H2S content, lb/oz – not more than 0.0037;

Hydrogen ion consentration – рН 4…8;

Mechanical impurities content, lb/oz – more than 0.0969;

Viscosity, mPa•s – 200;

Free gas content at the pump inlet, % - up to 50.

Gas-sand anchor is connected with the lower coupling of the lock support with the help of the tubing, connected with the upper sub. Or it can be installed on the standing valve body in the tubing pump, using the upper sub as a help. Gas-sand anchor operates on principles of centrifugal, gravitational and mechanical cleaning.

The anchor consists of a body, the upper part of which has perforations (b), through the perforations the pumped fluid goes to the inner part(c) of the anchor.

Getting to the cavity (c), the fluid goes down between the body walls and intake tube having slow velocity, which lets the gas, that the fluid contains, go up and then go out through the perforations (b) into the intake tube space.

The intake tube (3) is extended at the bottom (4), it helps to increase the flow velocity with mechanical impurities content. When getting into the intake tube opened at the bottom (3), the fluid flow changes direction on 180о, thus separating the mechanical impurities and the fluid. Through the inner cavity (d) of the intake tube (3), the fluid goes to the pump. The separated mechanical impurities are collected in the collector which consists of tubings and is installed on the bottom sub (5). The bottom tube has an end cap (6).