未开发油气储量不确定性潜力评价方法

Evaluation method for uncertain potential of undeveloped reserves

保有未开发储量一般都经过多轮次筛选评价,品位低,储层非均质性严重,整体动用技术配套性差,因而采用传统确定性参数评价筛选整体潜力存在一定的局限性。为此,研究构建了一套未开发储量不确定性潜力评价方法,针对油藏非均质局部“甜点”潜力,通过建立不同技术条件下单井控制可采储量与油藏参数的模型,计算不同技术、经济条件下单井控制可采储量的“甜点”界限,输入相关油藏参数的概率分布,计算得到目标油藏可动用概率。该概率反映了储量动用的难易程度,定量化描述了储量动用的风险和动用规模。应用该方法对中国石化探明未开发储量进行评价,在油价每桶40~70美元条件下,筛选可动用潜力(4 300~5 900)×10^(4) t。通过现场应用表明,该方法能为未开发储量评价筛选提供新的借鉴。

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) ×10^(4) t.Field application showed that this method can provide a new reference for the evaluation and screening of undeveloped reserves.