Artificial Lift System And Sucker Rod Pumps OGDCL PAKISTAN Prepared by Abdul Moiz 12-ME-130 Mech. Engineer UET Taxila Mobile # 0321-8975383

Topics To Be Covered Introduction Components & Working Selection of Pumping Method Advantages and Disadvantages Recommendations

Introduction Sucker rod pumping systems are the oldest and most widely used type of artificial system for oil wells Sucker rod pumping system are purely mechanical means of oil pumping and therefore prone to faults SRP applications cover very low down hole pressure wells, slim holes, multiple completions, high temperature and viscous oil.

Components & Working Sucker Rod pump consists of following parts: Prime Mover Crank Counter Weight Pitman Arm Walking Beam Sampson post(Tripod Stand) Bridle Polished Rods

Christmas Tree Down hole Pump Travelling Valve Standing Valve Working Prime mover causes rotary motion in the crank through V-belt The rotary motion results in reciprocating motion through pitman arm and walking beam. Horse head is connected to Polished rods through bridle

Christmas tree is set up on pumping surface. The Christmas tree consists of swab valves, wing valves, master valves and annulus valve The polished rod is connected to the down hole pump. Standing and Travelling valves control fluid flow in upward and downward stroke.

Schematic Diagram

Sucker Rod Pump Animation

SELECTION OF PUMPING METHOD Understanding The Reservoir:- Understanding the makeup of the producing reservoir, its pressure, and the changes that occur in it are important. Relationship between the reservoir fluid inflow and produced fluid outflow Determining bottom hole pressure and the inflow relationship of the fluids with changing reservoir and pump-intake pressure.

Bottom Hole Pressure Determination Calculating bottom hole pressures in the casing/tubing annulus through instruments The simplest instrument is a fluid-level sounder with a strip chart Knowing the reservoir and pump intake pressures during static and operating conditions will allow a determination of the well's production capacity

Inflow performance relationship (IPR) One of the most critical decisions in an artificial-lift system designing Reservoir Inflow Performance details the productivity index and IPR of fluids with changes in reservoir pressure. IPR predicts the future pressure performance required for maximum fluid flow.

Free gas and its Effect on performance It is the gas that remains in the solution when oil is pumped . It Increases the volume of fluid flow in to the pump. The free gas must be compressed at a pressure equivalent to head required to lift the fluid. Down hole gas separators and anchors are installed to increase efficiency.

ADVANTAGES Easy for personnel to operate to pump oil water or gas. Will operate for wide range of well producing characteristics Surface unit may be changed to other wells with minimum cost. Method is flexible to match pump displacement rate to well capability and well volume declines

Various degree of automation can be applied. High salvage value for surface and down hole equipment. Highly economical for repairing and servicing.

Disadvantages Pulling unit required to lift down hole equipment May cause solid formations such as paraffin and scales Crooked holes present a problem and may require special operating equipment Surface system is bulky and noticeable in on land and off shore equipments.

Production rates are usually very low compared to the modern pumping system. Over quantity of free gas may result in to decreased production and may result in affecting the pump. Mechanical damage and excessive wear to the pumps because of over pumping.

Recommendations Properly setting a well controller will help reduce severe over pumping. Load capable dynamometers must be installed in order to monitor changing loads on polish rods Variable slippage pumps should be installed to counter various solids entering the pumps. Care must be taken for handling the sucker rods during maintenance. Paraffin scrappers must be installed to avoid solid particles from entering.