Proper design and analysis of field tests requires two critical components: 1) availability of quality production data from appropriate control wells, and 2) a normalization process capable of isolating the impact of well and/or completion design changes on well performance.
We will present a normalization workflow currently employed in our Marcellus Shale assets. Normalization methodologies published by others will be summarized and discussed in this paper as well. Lastly, we will compare these published methodologies to our proposed approach, noting the pros and cons of the various approaches.
We begin by discussing an updated rate transient analysis (RTA) workflow (update of SPE-165711) that is based on analysis of 1,000+ Marcellus Shale wells with several years of production history, and incorporates several "lessons learned" in regard to non-uniqueness issues and input uncertainties. Details of our proposed normalization process will then be presented, which involves Production Data Analysis (PDA), Rate Transient Analysis (RTA), and analytical modeling. Lastly, we will explore a case history illustrating the value of this normalization process.
The case history will demonstrate the use of this normalization process to assess the value of different completion designs. This study will clearly illustrate the value of implementing an adequate normalization process to 1) assess field tests, 2) accurately forecast well productivity, 3) evaluate well economics associated with further testing, and 4) better understand why a new design performs differently from previous designs.