Well abandonment: cement sealing is mandatory

Decree 1631/06 (Aug 31, 2006) approves the province's 'Rules and Procedures for the abandonment of hydrocarbon wells' (Annex I) and incorporates them into the hydrocarbon environmental regulation (Annex VII of Decree 2656/99, which implements Environmental Law 1875; citation corrected by clarifying Decree 162/07). It covers every borehole deeper than 100 meters. It defines TWO types of abandonment — temporary (an exception, subject to a Monthly Abandonment Fee) and permanent — and creates the obligations that sustain the P&A market: (1) a mandatory Well Abandonment Plan, with a schedule, filed with the State Secretariat of Energy and Mining (60 days from entry into force; Ch. I.8-9 and IV.1); (2) the work may only be performed by companies registered in the Provincial Registry of Well Abandonment Operating Companies (I.10); (3) every new well must be categorized within 60 days of completion (I.11) and inactive or 'to-be-abandoned' wells are subject to deadlines by category (I.12); (4) permanent abandonment requires isolating every uncased permeable layer with cement plugs (2.1) and setting AT least two cement plugs (2.2) — a first plug with a retainer ≥30 m below the top of good cement sealed with ≥10 m of cement (2.4.1), and a second plug ≥50 m long covering ≥30 m below the surface-casing shoe (2.4.2) —, cutting the casing 2 m below grade, welding a steel cap and covering it with a 1 m³ concrete block (2.5), using api-standard cement (3.7). verif · Aug 31, 2006 ↗

In force since its publication in the Official Gazette (Art. 3 of the decree itself, issued Aug 31, 2006); clarifying Decree 162/07 applies retroactively as of Feb 16, 2007. verif · Aug 31, 2006 ↗

Concession holders, permit holders and contractors (required to file an Abandonment Plan, categorize wells and pay the Monthly Abandonment Fee for each temporary abandonment) and, above all, cementing and P&A service companies: only firms registered in the Provincial Registry of Well Abandonment Operating Companies may perform the work, and every permanent abandonment requires at least two cement plugs with tightness verification. It is regulatory demand with a licensing barrier — the pattern that favors the already-registered provider. verif · 2006-2026 ↗