Abstract
Multi-fractured horizontal wells (MFHW) is one of the most effective technologies to develop tight gas reservoirs. The gas seepage from tight formations in MFHW can be divided into three stages: early stage with high productivity, transitional stage with declined productivity, and final stage with stable productivity. Considering the characteristics and mechanisms of porous flows in different regions and at different stages, we derive three coupled equations, namely the equations of porous flow from matrix to fracture, from fracture to near wellbore region, and from new wellbore region to wellbore then an unstable productivity prediction model for a MFHW in a tight gas reservoir is well established. Then, the reliability of this new model, which considers the multi-fracture interference, is verified using a commercial simulator (CMG). Finally, using this transient productivity prediction model, the sensitivity of horizontal well’s productivity to several relevant factors is analyzed. The results illustrate that threshold pressure gradient has the most significant influence on well productivity, followed by stress sensitivity, turbulence flow, and slippage flow. To summarize, the proposed model has demonstrated a potential practical usage to predict the productivity of multi-stage fractured horizontal wells and to analyze the effects of certain factors on gas production in tight gas reservoirs.
Highlights
Natural gas is an indispensable energy resource which plays an important role on the world’s energy map
It is difficult to accurately and comprehensively reflect the actual flow state of fluid flowing into horizontal wells. To fill this gap, considering the seepage properties of the tight gas reservoirs and the steady-state seepage of fractured horizontal wells, we introduce the transient model of a matrix gas discharge radius
Our major conclusions can be summarized as follows: (1) The typical production process of fractured horizontal wells in tight gas reservoirs can be divided into three stages based on different seepage areas, flow media, and different seepage characteristics
Summary
Natural gas is an indispensable energy resource which plays an important role on the world’s energy map. To achieve an accurate productivity prediction, based on the characteristics of different production stages of fractured horizontal wells in tight gas reservoirs, different flow media in each seepage area, and different seepage mechanisms, it is necessary to establish corresponding productivity equations by considering the influence of factors such as: (a) threshold pressure gradient; (b) stress sensitivity effect; (c) slippage effect; and (d) high-speed non-Darcy effect. This comprehensive model is able atouseful predict productivity of the fractured was carried out. In the initial high-production stage, the artificial fractures are the primary flow medium, and
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
