A clastic gas reservoir with unconsolidated sandstone layers present great challenges for an effective development, because the tendency of these layers to produce sand. The objective of this paper is to present and highlight the applications of geomechanics in predicting critical drawdown pressure during the completion design and flowback test design with the ultimate purpose of minimizing the sand production. This paper will evaluate the perforation strategy for wells that may be prone to produce sand as part of the completion design optimization. A geomechanical approach was implemented to evaluate the interaction between stress field and the mechanical properties of rocks. A 1-D Mechanical Earth Model (MEM) was built and calibrated with offset wells in the nearby area. The overburden pressure was calculated by integrating density logs from the offset wells. The minimum horizontal stress was calibrated using closure pressure derived from the offset fracture analysis carried out in the offset wells. The rock elastic properties were calibrated with lab test data from an offset well locate ~2 km away from Well_A. Two case studies will be presented in this paper. The first case is Well_A drilled in a Devonian clastic reservoir, this vertical gas well was perforated with 60 degrees phasing guns. The well had a good performance during the flow back but the production was short-lived due to significant sand production. The second case is a blind test to validate the robustness of the methodology used in the first case study. An integrated approach was used to determine the most optimum way to perforate similar wells that has a potential to produce sand. Modified Lade failure criterion was used to predict the critical drawdown pressure because it takes into account the intermediate stress along with other geomechanical properties.

Open-hole multi-stage acid fracturing technology (MSF) has been widely implemented in the last few years in order to stimulate and maximize production rates from tight carbonate formations. A variety of factors can affect or contribute to the success of this technique which has to be taken into consideration to ultimately enhance the well performance. Among these factors, accurate well placement to maximize reservoir contact, fracture orientation relative to the stress direction, reservoir characteristics like lithology, stress, porosity development and optimum design of the well completion as well as proper execution of the stimulation treatment have strong influence on the final results and huge impact on the well productivity. This technical review of MSF jobs has made it possible to achieve a deeper understanding of the key factors controlling the outcome of the jobs and their relative importance. It will help optimize the future MSF candidate selection and their design, thereby achieving a high quality decision making process for completion selection. The objective of this paper is to discuss these factors and come up with conclusions and recommendations to optimize the use of this technology in future wells.