New technologies applied to horizontal wells fractured near gas-water contact in a gas giant. In a mature gas field with recovery factor over 80%, it is a big challenge to find new development opportunities. This is the case of Loma La Lata, a traditional gas field which mainly produces gas and condensate from Sierras Blancas reservoir. With permeabilities between 1 and 50 mD, the central part of the field has been developed since its discovery, with more than 300 wells drilled so far. This development strategy has left to the north-east, the deeper part of the reservoir, a long, slim, undrilled area, probably due to the proximity of the gas-water contact. This two-layered reservoir, with the lower, more depleted layer, containing the mobile water, came to offer a new development opportunity to the team. The pressure estimation per layer and the structural uncertainty in an undrilled zone were the main issues that had to be overcome. The use of mud logging and LWD allowed the team to adjust the landing point and navigation of the horizontal well within the thin upper layer. It was a fact that contacting the lower layer would have led to very low productivities, due to low pressure or to water break-in. Besides, these reservoirs are generally not productive without some form of mechanical stimulation, so the completion and stimulation design were fundamental for the project success. New fracturing technologies that allowed to make numerous small hydraulic fractures controlling the height growth in order not to contact the lower layer, seemed to be a good alternative to achieve better productivity. The use of gas, oil and water tracers appeared to be of great help to identify the frac ports that make the highest gas or water contributions. This information can be used later on to schedule a workover to shut certain ports. With only one well drilled so far, the successful navigation and completion operations together with the good productivity results, which were higher than expected, show that boundary reservoir development with horizontal wells seems to be promising.