Block 4 Well 16/1 is the first offshore well drilled in Lebanon by a consortium consisting of Total as operator, ENI and Novatek as non-operators. The drilling campaign undertaken by the consortium started on 3rd of March 2020 and ended on the 8th of May 2020. Upon completion of the well and in line with the Article 101 of Decree no. 10289/2013: Petroleum Activities Regulations (PAR), the Right Holder submitted a final geological and technical report detailing the findings.
The report consists of operational undertakings that start with the seabed survey to determine optimal location of well spud and designated safe zone, to the operations sequence, namely the types of drill bits, casings, drilling fluids, and cement used during operations. Specifically, the report covers the different sections: 36 inch, 26 inch, 16 ½ inch, 12 ¼ inch and finally the 8 ½ inch. This was followed by the plug and abandonment. Subsequent technical studies are being performed on the data retrieved from the well. Neither incidents nor recordable event was reported during the drilling operations.
In addition to the operational undertakings, the well report focused on the types of data acquisition performed:
• Mudlogging acquisition to enable reliable reservoir fluid evaluation and characterization.
• A full suite of Measure While Drilling (MWD) and Logging While Drilling (LWD) measurements.
The acquisition strategy consisted in recording while drilling a first set of basic data (well deviation, gamma ray and resistivity) for the well trajectory control, geological interpretation and stratigraphic correlation, as well petrophysical information. Measurements such as sonic while drilling was used to monitor formation pore pressure evolution along the well, overpressure ramp and data retrieved can be used for well to seismic tie.
Furthermore, cutting analysis was performed:
• Biostratigraphic analysis where samples were interpreted in terms of age and type of sediments.
• Thin section observations to focus on the sedimentological facies.
• Mineralogical interpretations to determine the type of mineralogical proportions within the rocks.
• Organic geochemistry to determine the type of organic matter found i.e. maturity and oil or gas prone potential of the rock.
Traces of gas were observed confirming the presence of a hydrocarbon system, but no reservoirs were encountered in the “Tamar” formation, which is the main target of this exploration well.
Unlike the recent discoveries in the Eastern Mediterranean (1999 – 2015) that encountered sands as the main reservoir, Well 16/1 witnessed a predominately carbonate lithology consisting of marls, calcareous claystones, limestones and clayey limestones similar in lithology to some of the discoveries in the Eastern Mediterranean after 2015. Consequently, further studies are to be made to adapt the previously used siliciclastic (Sand) model to the actual carbonatic environment discovered.
Coupled with the extensive geophysical coverage offshore Lebanon, the data derived from the well provided invaluable information for internal analysis.
The LPA performed a parallel study to the Operator’s one and resulted in the following findings:
• The petroleum system was proved to be functional.
• The formation tops, breaks in deposition and ages were identified from biostratigraphy and mineralogical analysis.
• Carbonate units are predominant in the zone around the well
• Different types of source rocks were identified, these include the potential for both oil and gas potential offshore Lebanon.
These converged with the findings reported by the Operator, based on geological and petrophysical analysis. However, further work is being conducted to understand the geological environment in which a potential reservoir could be located, by performing seismic interpretation and developing an elaborate sequence stratigraphy model.
Source: Lebanese Petroleum Administration (LPA).