THE JOURNEY TO THE MOFTINU GAS DEVELOPMENT PROJECT
- Written by Duncan Mackay, Senior Geoscientist & Alexandra Damascan, Country Manager
Natural gas was first encountered in the Moftinu area forty-seven years ago when the Moftinu-950 exploration well encountered gas that flowed to surface naturally before the well was abandoned in 1971 – the gas accumulation was deemed too small to be commercially exploited. Three more exploration wells were drilled in the area over the next sixteen years to discover the presence of a larger gas pool, but none of these wells successfully defined the presence of gas. After these failures, exploration activity ceased.
Fast-forward thirty years and Serinus Energy is in the final stages of preparation for construction of their 15 mmcf/d gas processing facility, through which 20 billion cubic feet of gas will flow over the next 15 years. The residents of Moftinu Mare remember the Spring of 2015 when the Moftinu-1001 well was drilled by Serinus Energy. Amongst the long-abandoned Moftinu well locations from the 1970s and 1980s, the well flowed gas from three gas reservoirs at 7.4 mmcf/d, producing a warm yellowy-orange flame that symbolized the burgeoning economic potential of hydrocarbon development in the Satu Mare County.
The presence of such a large gas accumulation within an area that had seemingly been exhaustively explored comes as a welcome event for the region. The project will be the largest single investment in the Satu Mare County in 2017, and will mark the beginning of a new economic industry. While the economic benefits of this new oil and gas activity are apparent, a bigger question for people in the region is: how much additional economic potential lies beneath the rich agricultural lands of Satu Mare? Serinus believes that with the implementation of new oil and gas exploration techniques – specifically the acquisition of three-dimensional seismic data – that the Moftinu gas project will be the first of many new commercial discoveries to be made by the company over the next several years.
MOFTINU: THE ROLE OF 3D SEISMIC IN THE FIRST COMMERCIAL GAS DISCOVERY IN SATU MARE AFTER HALF A CENTURY OF EXPLORATION
From the late 1960s to the early 1990s, exploration for oil and gas in the Satu Mare county was driven by the acquisition and interpretation of two-dimensional seismic data. These seismic data loosely blanketed the region in a patchwork of seismic lines that were typically spaced several hundred metres to a few kilometres apart. Despite using this data to guide the drilling of nearly 180 exploration wells over an area of nearly 3,000 km2, the early exploration efforts yielded numerous oil and gas shows, but failed to define a commercial hydrocarbon discovery. Even at Moftinu, 2D seismic indicated the potential presence of a large hydrocarbon trap, but failed to correctly identify the precise configuration of the structure, resulting in four failed exploration wells.
Although the earlier exploration wells in the Moftinu area may not have yielded commercial gas discoveries, the information of well results gave strong geological impetus for shooting an eighty square-kilometre 3D survey in 2012. This 3D seismic data provided a complete image of the subsurface features in the Moftinu area and showed that highest point in the Moftinu structure lay several hundred metres from any of the previously drilled wells, opening the possibility of sizeable closure that had not yet been tested by the drill bit. The 3D seismic survey allowed not only for the ‘true’ shape of the Moftinu structure to be accurately defined, but it also helped confirm the presence of gas using seismic amplitude modelling, which predicts the expected seismic response for a gas-filled (as opposed to wet) reservoir. These features are clearly present in the Moftinu seismic and strongly suggested that gas was present in the structure, even before drilling had commenced. Although seismic amplitude modelling using 2D data can provide some indications of gas, confidence in amplitude response remains very low in comparison with 3D data, which allows for robust seismic models and for bright amplitudes to be mapped in configurations that are consistent with uniform (in terms of elevation) gas-water contacts across a particular structure.
The high-confidence mapping of the Moftinu structure and positive indications of gas-filled sandstone ultimately gave the confidence to drill the Moftinu-1001 well (2014) amongst the decades-old failed Moftinu wells. The well encountered not only one, but at least three gas-bearing sands stacked on top of another. Despite covering an area of only a few square kilometres, the stacked nature of the reservoirs results in approximately 20 billion cubic feet of recoverable gas. At least two additional wells will be required at Moftinu to fully develop the gas resources in the structure.
SEISMIC ACQUISITION IN SATU MARE: A POSITIVE EXPERIENCE FOR SERINUS AND THE COMMUNITIES OF SATU MARE
During the most recent 3D seismic survey conducted by Serinus Energy (in 2014) one-hundred and eighty square kilometres of 3D data were acquired in the area north of Tasnad. The endeavour demonstrated a compatibility between the intense agricultural activity and hydrocarbon exploration activity in the area by minimizing interference with scheduled cultivation activities and by leaving no lasting impacts on the land. Two months of seismic-acquisition operations were conducted during the fall months when the fields had mostly been cleared of crops. These two months of activity were preceded by several months of careful land negotiations with near 2,000 land-title holders, along with several public information sessions and community consultation events. During these information sessions, stakeholders in the community were introduced to the technology used to generate and record seismic energy (i.e., vibroseis trucks and geophones, respectively), the methods used to deploy this technology in the field (i.e., laying out geophone cables and moving trains of vibroseis trucks through the acquisition area), and the minimal impact of the entire process on the landscape.
To date, Serinus Energy has acquired two 3D seismic data sets in Satu Mare county (Moftinu 3D, 2012; Santau 3D, 2014), covering a total of 260 km2 out of the nearly 3,000 km2 covered by the concession. These two seismic surveys were the first 3Ds to be shot in the Romanian Pannonian basin and other operators are now following suit.
Serinus expects to shoot additional 3D data to the east and north of Moftinu in the coming years. As with two previous seismic acquisition campaigns, frequent and open stakeholder engagement will ensure similarly successful seismic campaigns for both Serinus and for the involved communities.