İnvestigation of issues of increasing well productivity in the fields exploited under difficult conditions (in example of Buzovna-Mashataga field)

Abstract

The actuality of theme: Azerbaijan is not only one of the world's leading oil-producer countries, but also Azerbaijan is one of the world’s oldest oil-producers. Hydrocarbon resources (oil and natural gas) play an important role in the economy of the Republic of Azerbaijan. In 1921, exploration works were expanded due to the decline in oil production, and following these events a number of new oil fields were discovered and put into operation in Azerbaijan (especially Gala, Buzovna-Mashtagha etc.) and oil extraction in 1941 reached to 23.6 million tons, which was about 76% of the Former Soviet Union’s total oil production on that time. In this Master of Science thesis, selection of appropriate measures against sand production formation in Buzovan-Mashtagha field, one of the oldest oil fields of Azerbaijan is being studied. The field is located in the northern-east part of the Absheron Peninsula, 20km from Baku, between Mashtagha and Buzovna villages. Buzovna - Mashtagha oil field is located in the East Absheron OGR and forms part of the Kurdakhani- Gala – Zyra anticlinal fold. The studies carried out in the field have revealed that the Buzovna - Mashtagha belongs to the type of buried oil fields. The fold is divided into the northern-southern-central sections by single longitudinal tectonic fault with an amplitude of 200-250m. The oil and gas resources of the field is mainly formed in the PK, NKP, NKG Suits of the Lower Productive Series and in X, VII, V, IV, and II horizons of the Upper Productive Series is distributed in separate tectonic blocks according to the local areas. The field was first discovered in the Southern Buzovna area by the exploration well # 1/1056 drilled in 1940; the well was penetrated the IV KS horizon, with a daily oil production of 85.0 tones. Oil and gas content of other suits in the Mashtaga area was discovered in 1944. By 1954, oil and gas resources of productive layers of the field and their contours were determined. The porosity of reservoirs s varies between 19-24% for NKG, NKP, KS and PK suits, ranging from 0.100 to 0.300 mkm², respectively. Buzovna - Mashtagha field’s oil belongs to the types of fluids that do not follow Newton’s law due to its physical characteristics. Especially, it should be noted that because of the fact that oil-gas reservoirs are very poorly cemented and very fragile sand productions are intensively developed while exploiting the wells, during the short exploitation period wells are disrupted for technical reasons and some major problems occur while trying to effectively development of the reservoirs. It was suggested that the classification model to be used to increase oil extraction considering that the field is at the stage of production decline. Results concluded in this thesis can be practically implemented in planning of the development program of onshore fields.