| 摘要 |
<p>Drilling, completing or workover of a well, particularly an oil and/or gas well, is carried out using a fluid which includes a continuous phase including an ester of the formula (I): (R2)p-Ph-(CH2)m-COO-(AO)n-R1 where R1, AO, n, m, Ph, R2 and p have defined meanings and particularly where the esters are alkyl or alkenyl benzoate esters. These esters are beneficial by having a range of viscosities, especially extending to low viscosities, and attractive toxicological and environmental profiles for use in drilling, completion and/or workover of wells.</p> |
