In order to improve production and subsequent well economics in the Wolfcamp formation in Eddy County, New Mexico, horizontal drilling has been employed for the last seven years. Current stimulation practices in these horizontal wells involve hydraulically fracturing with proppant in multiple stages. The effectiveness of the various fracturing treatments on production responses is of interest, because any optimization or changes that can reduce stimulation costs improves profit. In addition, with the current shortages in all mesh sizes of sands, anything which reduces the quantities needed to effectively stimulate wells is a plus. Production from a localized group of horizontal Wolfcamp wells was examined to establish the impact scenario that proppant choice made on performance. It was found that decline rates were the same or better on wells fracture treated using a significantly lower volume of an Ultra-Lightweight proppant compared to those wells treated with regular sand. This reduction in proppant used also resulted in a savings ranging from 4% to 33% of the stimulation costs. Introduction The Wolfcamp formation in the study area of Eddy County, New Mexico, was deposited along a paleo shoreline and is a sequence of dolomite and shale layers above the producing interval with a sequence of limestone and shale layers below. Fig. 1 is an illustration of a typical openhole log. The major producing segment is the basal Abo, or Abo-Wolfcamp transition interval, which developed, as a fine-grained (re-crystallized) dolomite. When developed this fine grained characteristic, also known as sucrosic texture, is somewhat comparable to sandstone in terms of reservoir quality. Vertical wells in the area were first drilled in the 1970's with poor success. This lack of success was due to the formation being discontinuous horizontally and vertically limited; therefore making it difficult to hit the target with a vertical wellbore. Net Pay thickness is approximately 20 feet. Originally, the Bottomhole Reservoir Pressure was about 2000 psi. The Bottomhole Static Temperature is 105°F. Average porosity is 9% to 12% and average permeability <0.1 Millidarcy, with water saturations from 20% to 50%. Anticipated recoverable gas per well in the better part of the field is 2 BCF on 320 acres drainage. In 2001 to 2002 the first horizontal wells were drilled in the area with success. First stimulation attempts were made using hydrochloric acid given the carbonate lithology. This was somewhat successful however, propped fracture treatments proved to have a more significant effect on production. It has been determined from one of these wells in the study area that induced fractures have a 330 - 150 azimuth (NW to SE). This paper presents comparisons of propped fracture treatments utilized to achieve higher production capabilities. At the heart of this production improvement is the concept of a partial monolayer of proppant in the created hydraulic fracture 1–35. A partial monolayer is achieved at 0.06 to 0.09 pounds per square foot concentration of proppant over the fracture face. In this concentration range the optimum conductivity is observed for at most closure stresses. Included in this study will be the effectiveness of an Ultra-Lightweight proppant compared to traditional proppants. The Ultra-Lightweight proppant has been described before and evaluated in other studies 6–15. Of importance will be the effect on production decline of the different treatments and the differences in job costs.