The Next Step in Conventional Reciprocating Mud Pump Technology

Abstract

Abstract Recent developments in reciprocating mud pump technology provide added value for operators, drilling contractors, and MWD/LWD (measurement while drilling/logging while drilling) service providers. Utilizing current proven conventional triplex (3-cylinder) pump designs and adding two cylinders provides an increased performance envelope, reduces pulsations on the rig structure and piping, and substantially increases data rate-transfer bandwidth during MWD/LWD operations. Current data rate transfer for MWD/LWD when using reciprocating pumps are limited to frequencies below the first dominant frequency. Using a comparable horsepower quintuplex (5-cylinder) pump increases the data transfer rate 66% over current triplex reciprocating pumps. Due to the shorter stroke of a comparable horsepower quintuplex pump, the pump can also be operated at higher stroke rates that produce an additional 33% gain in frequency bandwidth. This is achieved through increased frequency of the additional pump cylinders and the ability to operate the pump at higher pump speeds. The inherent design attributes of conventional quintuplex pumps reduce fluid flow variation (pulse) versus comparable horsepower triplex pumps. The five operating cylinders are timed at 72° whereas conventional triplex pumps are timed at 120° intervals per 360° of pump rotation. The additional cylinders reduce flow variation of the quintuplex to 7 percent versus a 23 % flow variation for conventional triplex pumps. This paper focuses on advantages of using a conventional five cylinder design horizontal mud pump versus an equivalent horsepower conventional three cylinder design. For comparison a EQ-2200 will be tested versus a E-2200.The discussion includes specification comparisons, weights, external envelope dimensions and comparisons of fluid flow variation (pulse) performance that translates into reduced vibration on the rig and increased MWD/LWD data rate transfers. The EQ-2200 is a 2,200 horsepower quintuplex pump and the E-2200 is a 2200 horsepower triplex pump. Both pumps are crankshaft-slider driven and both are rated at 7500 PSI working pressure. Though both series have equivalent horsepower, in contrast, the pulse signature of the EQ series is greatly reduced compared to that of the E series, thereby increasing the performance envelope for MWD/LWD operations. In addition weights and dimensional envelopes of the EQ series are less than the E series.