Evaluation method for uncertain potential of undeveloped reserves

Abstract

Retained undeveloped reserves are generally low-grade and undergone multiple rounds of screening and evaluation. The reservoir is highly heterogeneous and the overall production technology is poorly matched.Therefore, the use of traditional deterministic parameters to evaluate and screen the overall potential has limita-tions and a set of evaluation method for the uncertain potential of undeveloped reserves has been constructed.In the view of local "sweet spot" potential of heterogeneous oil reservoirs, a model for controlling recoverable reserves and reservoir parameters in a single well under different technical conditions was established to calculate the "sweet spot" limit of single-well-controlled recoverable reserves under different technical and economic conditions, input the probability distribution of relevant reservoir parameters, and calculate the recoverable probability of target reservoir.The probability reflected the difficulty of reserve production, and quantitatively described the risk and scale of reserves production.The method was applied to evaluate the proved undeveloped reserves of SINOPEC. Under the oil price of 40-70 ＄/BBL, the exploitable potential was screened as (4 300-5 900)×104 t.Field application showed that this method can provide a new reference for the evaluation and screening of undeveloped reserves.

Keywords

• undeveloped reserves
• uncertainty method
• evaluation for hydrocarbon potential
• oil field exploration