ABSTRACT
Tarim Oilfield has developed five major oil and gas fields in Tazhong, Lunnan Lungu, Donghe Yaha Yingmai, Kuqa, and Southwest Tarim. The reservoir types can be divided into medium porosity and medium (high) permeability sandstone reservoir, low porosity, and low permeability sandstone reservoir, fracture pore sandstone reservoir, fracture pore cave carbonate reservoir, and cave carbonate reservoir. The current reservoir protection design and construction are mainly based on acid soluble weighting materials, low water loss, and shielding temporary plugging technology. Through the analysis, it is found that the reservoir protection in the current drilling stage is not targeted, the whole process of reservoir protection has not been effectively implemented, and the evaluation method of reservoir protection is unreasonable. Different types of reservoir protection schemes are established through research. The reservoir with medium porosity and medium permeability is shielding temporary plugging technology, low water loss, appropriate salinity, and acid-soluble weighting material; the protection of low porosity and low permeability reservoir is temporarily blocked by shielding of small particles; the damage mechanism of fractured porous sandstone reservoir is fracture leakage, basic fast phase trap, salt\water\alkali sensitivity. The protection measures are low damage drilling fluid system, leak prevention and plugging technology while drilling, acid-soluble plugging materials, membrane temporary plugging, etc; The fractured vuggy carbonate reservoir mainly needs leakproof, and the cavernous carbonate reservoir is less damaged. It is recommended not to add ultra-fine calcium carbonate for shielding and temporary plugging. The research also established the prediction software to predict the fluid sensitivity and the ideal filling software to design the fine reservoir protection formula. The results provide a preliminary idea for establishing an effective reservoir protection system in the drilling stage of Tarim Oilfield, which is conducive to providing the pertinence and effect of reservoir protection in the drilling stage of Tarim Oilfield.39
