CHRONOSTRATIGRAPHICALLY BASED RESERVOIR MODEL FOR CENOMANIAN CARBONATES, SOUTHEASTERN IRAQ OILFIELDS

The Cenomanian – Turronian sedimentary succession in the south Iraq oil fields, including Ahmadi, Rumaila, Mishrif and Khasib formations have undergone into high-resolution reservoir-scale genetic sequence stratigraphic analysis. Some oil-wells from Majnoon and West-Qurna oil fields were selected as a representative case for the regional sequence stratigraphic analysis. The south Iraqi Albian – Cenomanian – Turronian succession of 2nd-order depositional super-sequence has been analyzed based on the Arabian Plate chronosequence stratigraphic context, properly distinguished by three main chrono-markers (The maximum flooding surface, MFS-K100 of the upper shale member of Nahr Umr Formation, MFS-K140 of the upper Mishrif carbonates, and MFS-K150 of the lower Khasib shale member).Three 3rd-order genetic mega-sequences were embraced between the cited chrono-markers. The markers have been considered as regional key-surfaces for the Late Albian – Cenomanian to Early Turonian and Late Turonian to Early Coniacian stratigraphy of the south Iraqi oil fields. Eight 4th-order genetic meso-sequences (MS1 to MS8) have been established, comprising multiple 5th-order high-frequency (HF) lithofacies cycles, successively arranged in the mega-sequences without disturbance. MFS-K135 (this study), MFS-K140, MFS-K150 and Seven successive regional chrono-markers [MFS-K120, MFS-K125 (this study), MFS-K130, and MFS-K160 of upper Khasib shale member] started from lower Ahmadi shale member, identify these meso-sequences. Associated fifteen key-surfaces (K121, K122, K123, K124, K125, K126, K127, K128, K129, K131, K132, K133, K134, K141 & K142) have been described as well. The meso-sequence 1 signifies Ahmadi lithofacies buildups, whereas; the other meso-sequences represent Mishrif lithofacies buildups. The Rumaila carbonates come across the first HST-unit of the meso-sequence 2. The meso-sequence 8 represents the Khasib carbonate facies buildups. The depositional super-sequence is terminated by type-1 sequence boundary SB-K150 at the top of the Mishrif Formation, created by maximum regression (MR). The study declares 15 reservoir syn-layers and 9 non-reservoir layers; each is essentially characterized by HF-single-lithofacies-cycle and lateral continuity pattern. This syn-layer model can be used as sequence steering technique for carbonates heterogeneity aspects, in the south Iraqi oil fields to control fluid dynamics in primary and secondary development projects

A MODIFIED WATER INJECTION TECHNIQUE TO IMPROVE OIL RECOVERY: MISHRIF CARBONATE RESERVOIRS IN SOUTHERN IRAQ OIL FIELDS, CASE STUDY

A modified water injection technique has organized by this study to improve oil recovery of the Mishrif reservoirs using polymerized alkaline surfactant water (PAS-Water) injection. It is planned to modify the existing water injection technology, first to control and balance the hazardous troublemaker reservoir facies of fifty-micron pore sizes with over 500 millidarcies permeability, along with the non-troublemaker types of less than twenty micron pore sizes with 45 to 100 millidarcies permeability. Second to control Mishrif reservoirs rock-wettability. Special core analysis under reservoir conditions of 2250 psi and 90 °C has carried out on tens of standard core plugs with heterogeneous buildup, using the proposed renewal water flooding mechanism. The technique assures early PAS-water injection to delay the water-breakthrough from 0.045 – 0.151 pore volumes water injected with 8 – 25% oil recovery, into 0.15 – 0.268 pore volumes water injected with 18 to 32% improved oil recovery. As well as, crude oil-in-water divertor injection after breakthrough, within 0.3 to oil0.65 – 0.85-pore volume of water injected to decrease water cut 1 four 0 to 15%. The overall progress of the PAS-water injection has achieved residual oil mobility of 65%, and upgraded the 35 – 50% oil recovery range by less than three pore volume water injected with 20 – 60% water cut, compared with the same oil recovery range by more than ten pore volume water injected with around 70% water cut. The ultimate oil recovery improved by this technique is from 70% via more than 20 pore volume water injected with over 95% water cut by usual water injection, to 85 – 90% via 6.4 pore volume water injected with over 90% water cut by the modified water injection. The technique succeeded to lower the end-point mobility ratio to 1.5 from above five by usual water injection. It is highly recommended to use ten micron mesh filter at the main injection site and four or five micron mesh filter at the injector sites; to avoid more than 80% of the suspended particles and save as much as possible the overall reservoir facies from permeability damage

Fluorescence of coral larvae predicts their settlement response to crustose coralline algae and reflects stress

Multi-coloured homologues of the green fluorescent protein generate some of the most striking visual phenomena in the ocean. Despite their natural prominence in reef-building corals and widespread use in biotechnology, their biological role remains obscure. Here, we experimented with larvae of Acropora millepora to determine what can be learned about a coral larva or recruit from its fluorescent colour. We performed 12 crosses between seven A. millepora colonies representing differing fluorescence phenotypes, the larvae of which were exposed to a natural settlement cue (crustose coralline algae) and heat–light stress. Parental effects explained 18 per cent of variation in colour and 47 per cent of variation in settlement. The colour of the larval family emerged as a predictor of the settlement success: redder families were significantly less responsive to the provided settlement cue (p = 0.006). This relationship was owing to a correlation between parental effects on settlement and colour (r2 = 0.587, p = 0.045). We also observed pronounced (16%) decline in settlement rate, as well as subtle (2%), but a statistically significant decrease in red fluorescence, as a consequence of heat–light stress exposure. Variation in settlement propensity in A. millepora is largely owing to additive genetic effects, and is thought to reflect variation in dispersal potential. Our results suggest an optical signature to discriminate between long- and short-range dispersing genotypes, as well as to evaluate stress. Further research in this direction may lead to the development of field applications to trace changes in coral life history and physiology caused by global warming

Megalencephalic Leukoencephalopathy with Cysts without MLC1 Defect Two Phenotypes

Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is an autosomal recessive disease characterized by early infantile macrocephaly and delayed motor and cognitive deterioration. Magnetic resonance imaging (MRI) shows diffusely abnormal and swollen cerebral white matter and subcortical cysts. On follow-up, atrophy ensues. Approximately 80% of MLC patients have mutations in MLC1. We report 16 MLC patients without MLC1 mutations. Eight retained the classical clinical and MRI phenotype. The other 8 showed major MRI improvement. They lacked motor decline. Five had normal intelligence; 3 displayed cognitive deficiency. In conclusion, 2 phenotypes can be distinguished among the non-MLC1 mutated MLC patients: a classical and a benign phenotype.link_to_subscribed_fulltex