A successful tight-gas development is best defined based on economic criteria. Although operators may use different metrics to define economic success, achieving a positive NPV can generally be considered a key indicator. Focusing solely on technical success (i.e. a well producing at the expected gas rate) is not an appropriate definition of success. Some wells will perform better than others due to variations in reservoir quality, connected volume, or issues with fracture stimulation—this is an inherent part of tight-gas development. This breakout session will discuss the key stages of a tight-gas development that determine its success.

For a tight-gas development to be economically successful, the first requirement is a realistic field development plan based on the chosen development concept. This may include the number of wells, well types, stimulation approach, surface facilities, and related considerations. A critical element in preparing such a development plan is a robust appraisal programme that collects sufficient data over an adequate period to capture the essential reservoir parameters. These parameters inform the optimal development concept (i.e. optimal well spacing, drainage extent, permeability, effective fracture half-length, and fluid properties).

Tight-gas developments typically require drilling a large number of wells—more than conventional gas developments. These wells may be vertical or horizontal, depending on reservoir characteristics such as gross thickness and fracture height growth. Generally, tight-gas developments have a higher probability of economic success when drilling costs account for less than half of the total well cost, with the remainder attributed primarily to fracturing. During the early stages of a project (appraisal), drilling costs tend to dominate, and there must be a clear pathway to reduce these costs during the development phase. In addition, stimulation costs often become an increasingly large proportion of total well costs, particularly where multi-stage or high-proppant-volume fracturing is applied. Continuous reduction of overall well costs is critical to project success; without this, the development is unlikely to be economically viable.

The final hallmark of a successful development is ensuring that the development strategy is aligned with the production profile over the full well life. Many unsuccessful projects fail to adequately account for the production decline trend, which is typical (and unavoidable) in tight-gas wells. Liner and production tubing are often oversized based on conventional well designs, or permanent tubing is selected to accommodate fracture stimulation without considering future production challenges. In particular, insufficient planning is often made for managing liquid loading in later life. Maintaining economic viability requires a completion design that supports high-rate, high-pressure stimulation while also providing flexibility to mitigate liquid loading as the well matures. Consideration of future workover options (e.g. installation of velocity strings) is therefore essential in any tight-gas development.

The session leaders will present a short set of slides based on the above content (15 minutes).
Following this, participants will be divided into three groups to brainstorm on the following topics (20 minutes):

• Define the requirements for an appraisal programme for a tight-gas development
• Define a strategy for reducing drilling, completion, and stimulation costs over the project lifetime
• Define a completion strategy that supports fracture stimulation, initial gas production, and late-life production when liquid loading becomes a constraint

Each group will then present its key observations to the wider audience (3 × 5 minutes = 15 minutes).