A new experimental setup for the study of bubble coalescence and bubble jet interactions in microgravity conditions is presented. The section consists of a cavity full of liquid containing two bubble injectors whose separation distance and relative orientation angle can be controlled. Injection of bubbles is based on the generation of a slug flow in a capillary T-junction, which allows a control of bubble size and velocity by means of liquid and gas flow rates. Individual and collective behaviour of bubbles injected in the cavity has been studied. On ground results on the individual trajectories, maximum distance reached, and the delimitation between turbulence and buoyancy regions are presented. The influence on these results of the inclination angle of one injector with respect to gravity has also been considered. A good knowledge of bubble jets behaviour in microgravity will enhance the development of space technologies based on two-phase systems.

INTRODUCTION When the natural energy of a reservoir is not enough in order to elevate the oil to the surface, it is necessary to use an artificial lift system that supply the additional energy required to continue the exploitation of the reservoir. Likewise, the artificial lift system is installed to increment the production in flowing wells. This is achieved by the energy that is added to fluids in the bottom of the well. The hydraulic pumping, is an artificial lift system that transmits energy in the bottom of the well by a power fluid that flow through a pump. There are two types of hydraulic pumping; the denominated piston type, that consists in a pair of reciprocating pistons, where one of them is driven by the power fluid and the other pumping the well fluids. And the hydraulic pumping jet type, which converts the pressurized power fluid to a high velocity jet that is mixed directly with the well fluids. A description is presented and the result reached in a pilot test of hydraulic jet pump, effected in the Balam 91 well of the Ek-Balam field. BACKGROUND The Ek-Balam field was discovered when the Ek 101 and Balam 1 wells were drilled in March 1991 and January 1992 respectively. This reservoir is located at 95 km to the N 10° W of Carmen City, Campeche, in the Gulf of Mexico. The geophysical and petrophysical evidence allowed to define the existence of a saline intrusion lengthened with NW-SE orientation that divides the reservoir into two blocks, that have similar but independent characteristics (figure 1). The first tests indicated the possibility that had been found a field of great magnitude. However, the initial production rate declined quickly as well as the static pressure of the reservoir, which originally was rated from 7,850 psi for Ek up to 8,200 psi for Balam. The producing formation belongs to the Upper Jurassic Oxfordian sandstone and constituted mainly by light consolidated sand, which cause that fine solid materials be carried when the pressure drop in the reservoir is high, occasioning problems in the surface and bottomhole installations, as well as in the bottom of the well for their deposition. How a days, the wells in operation in the Ek-Balam field produce through the artificial lift denominated Electro Submersible Pump (ESP). However, with the purpose of analyzing another option that could complement to the utilized system, was proposed the development of a test of hydraulic jet pump (HJP) in the Ek-Balam field. The Balam 91 well is located in the Balam-TE platform, in the Ek-Balam field that belongs to the PEMEX Northeast Marine Region in the Campeche Bay, Gulf of Mexico. Hydraulic pumping. The hydraulic pumping operate for the transmission of potential energy that is effected in a pump located in the bottom of the well to the produced fluids. The hydraulic pump in the bottom acts like a transformer converting the energy of a power fluid to potential energy or pressure. Exist two types of installations: fixed and free pump. The fixed installation consists of a down hole pump attached to the end of a tubing string; the free pump is design in order to permit it installation inside of the tubing, which normally is coiled tubing (CT), in order to drive the power fluid. This allows recovering the pump with inverse circulation. There are two forms to inject the power fluid; in closed or open circuit. Hydraulic pumping. The hydraulic pumping operate for the transmission of potential energy that is effected in a pump located in the bottom of the well to the produced fluids. The hydraulic pump in the bottom acts like a transformer converting the energy of a power fluid to potential energy or pressure. Exist two types of installations: fixed and free pump. The fixed installation consists of a down hole pump attached to the end of a tubing string; the free pump is design in order to permit it installation inside of the tubing, which normally is coiled tubing (CT), in order to drive the power fluid. This allows recovering the pump with inverse circulation. There are two forms to inject the power fluid; in closed or open circuit.