Management of Artificial Lift Planning Deployment for Improved Field Development Plan

摘要

Artificial lift is generally required to extend field-life beyond the period of natural flow. In the course of the reviews and studies we performed, we noted artificial lift had not been given sufficient consideration at initial design phase. Due to the pressure to maintain the field production, operators often choose a phased artificial lift deployment to cope with the learning curve, risks and uncertainties, which typically includes: 1. A first phase (Phase-1) of artificial lift is screening and concept testing to evaluate artificial lift options; 2. A second phase (Phase-2) involves deployment to a group of wells for a selected option; 3. A final phase (Phase-3) is the full field implementation. This paper presents an efficient and effective workflow to select the most suitable candidates for Phase-2. Lessons learnt based on the implementation of workflow in real-life case studies will be shared as well: 1. First, a well selection process is performed to review inactive strings and/or low performers that are most impacted by such issues as reservoir pressure declined / high water production. Cased-hole saturation logs (PNC log) and static pressure log measurements are used to build an understanding of areal pressure and water saturation distribution and to further identify localized pressure sinks and watered-out areas. The understanding gained upon reviewing the well-based surveillance data is used to identify candidates for artificial lift application. 2. Then, the well candidates which are grouped by categories of issues and different reactivation options are screened for each group of wells. A score-based ranking process is applied to sort candidates on urgency, value or impact of artificial lift and possibly other criteria, using production history and surveillance data. 3. Finally, results per well are reconsolidated to reservoir / field level and used to support a field-wide concept, which allows to extract valuable field scale requirements (e.g. the determination of the gas-lift volume requirement for gas-lift planning etc.). This workflow greately helps to understand the root cause of performance issues and to select the most suitable artificial lift concept (including considering well pre-conditioning needs such as water shut-off). It leads to exploring and defining artificial lift concepts and helps to focus on the field development plan and detail engineering study at a very early stage.