Matrix aciding and microporosity changes of the fabrics observed in Arsuz-İskenderun (Hatay) area

This study aims are determining the field and petrographic properties of sandstones observed in Arsuz-İskenderun (Hatay) region and micro-size porosity changes in acidizing stages. In the field, sandstones are observed sequentially with claystones. Claystones and sandstones are medium-thick bedded in the Aktepe formation The thickness of the claystones varies between 20 cm and 33 cm, while the thickness of the sandstones is between 25 cm and 40 cm. In the Kızıldere Formation, sandstone and claystone sequences are commonly observed, the thicknesses of gray-yellow sandstones are between 10-50 cm and the thickness of gray-colored claystones are between 2-30 cm. Tectonic cracks and oxidation are observed in both formations. The sandstones of the Aktepe formation which shows very fine-grained sandstone characteristics have more quartz grains than the other components and the binding material is matrix. Rock fragments are observed relatively to quartz and feldspar grains in the Kızıldere formation sandstones. It consists of rock fragments, fossil shells, limestone grains and igneous rock fragments. The binding material is calcite cement and sandstone is named as lytic arenite. The first step of reservoir rock acidizing is HCl acidizing and process is experimentally provided by capillarity. The dilution rates of 7.5% -15% -30% HCl acid solutions 100 minutes of effective distances of 0.6-0.8-1.1 cm and dissolved rock amounts 32.82-34.02-35.54 g, respectively. In acidizing process, the average porosity analysed with Micro-CT is 39.6% of acidified samples with 15% diluted acid, that are most commonly applied in well production, .and non-acidified samples. Equivalent results were obtained with porosity values measured by well logs. There is an increase in porosity of about 16% with acidizing. Pores were bonded together by acidizing and pore size increased by about 20%. The change in the pore throat by acidizing is 51%. Calculation of porosity of rocks by Micro-CT and image processing methods can be analysed faster than other methods. The porosity values of the sandstones of Kızıldere formation indicate reservoir rock.